Glossaire des acronymes et termes courants

• ACRONYMSACEA – Association des constructeurs Européen d’automobiles
• AGMA –  Association américaine des fabricants d’engrenages
• API – Institut américain du pétrole
• ASLE – Société américaine des ingénieurs en lubrification (American Society of Lubrication Engineers)
• ASME – Société américaine des ingénieurs en mécanique (American Society of Mechanical Engineers)
• ASTM – température de pompage limite (American Society for Testing and MaterialsBPT – Borderline Pumping Temperature)
• BTU – Conseil des ressources atmosphériques de Californie (British Thermal UnitCARB – California Air Resources Board)
• CCS – simulateur de démarrage à froid (Cold Crank Simulator)
• CEC – Conseil européen de coordination pour les énergies renouvelables.
• CMA – Association des fabricants de produits chimiques (Chemical Manufacturers Association)
• cP – CentiPoise
• cSt – CentiStoke
• COC – Cleveland Open Cup
• DIN – Deutsche Industrie Norm
• EGR – Recirculation des gaz d’échappement (Exhaust Gas Recirculation)
• EHD or EHL – Lubrification élastohydrodynamique (Elastohydrodynamic Lubrication)
• EMA – Association des constructeurs de moteurs (Engine Manufacturers Association)
• EP – Extrême pression (Extreme Pressure)
• ILSAC – Comité international de normalisation et d’homologation des lubrifiants (International Lubricant Standardization and Approval Committee)
• ISO – Organisation internationale de normalisation (International Organization for Standardization)
• JAMA – Association des constructeurs japonais d’automobiles Inc (Japanese Automobile Manufacturers Association Inc)
• JASO – Organisation japonaise de normalisation automobile (Japan Automobile Standards Organization)
• MSDS – fiche de données de sécurité (Material Safety Data Sheet)
• NLGI – Institut national des graisses lubrifiantes (National Lubricating Grease Institute)
• NMMA – Association nationale des constructeurs de bateaux (National Marine Manufacturers Association)
• PAO – Polyalphaoléfine (Polyalphaolefin)
• SAE – Société des ingénieurs de l’automobile (Society of Automotive Engineers)
• STLE – Société des tribologues et des ingénieurs en lubrification (Society of Tribologists and Lubrication Engineers)
• SUS or SSU – Secondes universelles Saybolt (Saybolt Universal Seconds)
• TAN –Indice d’acidité totale (Total Acid Number)
• TBN – Indice de base total (Total Base Number)
• VI – Indice de viscosité (Viscosity Index)
• VII – Indice de viscosité amélioré (Viscosity Index Improve)
• ZDP – Dithiophosphate de zinc (Zinc Dithiophosphate)

TERMES COMMUNS

Abrasion – Usure, meulage ou frottement par friction. L’abrasion est généralement due à la présence de matières étrangères telles que des saletés, des gravillons ou des particules métalliques dans le lubrifiant.

Viscosité absolue – Viscosité absolue – Le produit de la viscosité cinématique et de la densité.
Viscosité absolue (n) = Viscosité cinématique (y) x Densité (p).

Acide – Solution corrosive formée par la combinaison d’atomes d’hydrogène et d’oxygène avec des radicaux métalliques ou des métaux. Les solutions acides peuvent être neutralisées avec une base ou une solution alcaline.

Indice d’acidité – Mesure de la quantité de KOH nécessaire pour neutraliser tout ou partie de l’acidité d’un lubrifiant.

Additif – Matière ajoutée à un produit de base pour en modifier les propriétés, les caractéristiques ou les performances.

Adhésion – Propriété d’un lubrifiant qui lui permet de s’accrocher ou d’adhérer à une surface solide. L’usure se produit lorsque des surfaces entrent en contact, se soudent et se cisaillent.

Entraînement d’air – L’incorporation d’air sous forme de bulles dispersées dans un fluide. Fréquent lorsqu’une quantité inadéquate d’agent antimousse est ajoutée pour réduire la formation de mousse.

Température ambiante – Température de l’air entourant le point d’application.

Anhydre – Exempt d’eau.

Antimousse – Additif utilisé pour supprimer la tendance au moussage des lubrifiants en service. Une quantité inadéquate d’antimousse entraîne l’entraînement de l’air, ce qui entraîne également des problèmes de lubrification.

Antigel – Solution présente dans le système de refroidissement d’un moteur qui abaisse le point de congélation du liquide de refroidissement et augmente son point d’ébullition.

Antioxydant (inhibiteur d’oxydation) – Additif qui retarde l’oxydation des lubrifiants.

Anti-usure – Additifs qui forment de fines pellicules tenaces sur les pièces chargées pour empêcher le contact métal contre métal.

Viscosité apparente – Mesure de la viscosité d’un fluide non newtonien à une température et un cisaillement donnés. La viscosité est exprimée en unités de centipoise (cP).

Cendres – Dépôts métalliques formés dans la chambre de combustion et d’autres parties du moteur pendant le fonctionnement à haute température.

Cendres (sulfatées) – La teneur en cendres d’une huile, déterminée en carbonisant l’huile, en traitant le résidu avec de l’acide sulfurique et en l’évaporant à sec. Exprimée en % de la masse.

• ACRONYMSACEA – Association des constructeurs Européen d’automobiles
• AGMA –  Association américaine des fabricants d’engrenages
• API – Institut américain du pétrole
• ASLE – Société américaine des ingénieurs en lubrification (American Society of Lubrication Engineers)
• ASME – Société américaine des ingénieurs en mécanique (American Society of Mechanical Engineers)
• ASTM – température de pompage limite (American Society for Testing and MaterialsBPT – Borderline Pumping Temperature)
• BTU – Conseil des ressources atmosphériques de Californie (British Thermal UnitCARB – California Air Resources Board)
• CCS – simulateur de démarrage à froid (Cold Crank Simulator)
• CEC – Conseil européen de coordination pour les énergies renouvelables.
• CMA – Association des fabricants de produits chimiques (Chemical Manufacturers Association)
• cP – CentiPoise
• cSt – CentiStoke
• COC – Cleveland Open Cup
• DIN – Deutsche Industrie Norm
• EGR – Recirculation des gaz d’échappement (Exhaust Gas Recirculation)
• EHD or EHL – Lubrification élastohydrodynamique (Elastohydrodynamic Lubrication)
• EMA – Association des constructeurs de moteurs (Engine Manufacturers Association)
• EP – Extrême pression (Extreme Pressure)
• ILSAC – Comité international de normalisation et d’homologation des lubrifiants (International Lubricant Standardization and Approval Committee)
• ISO – Organisation internationale de normalisation (International Organization for Standardization)
• JAMA – Association des constructeurs japonais d’automobiles Inc (Japanese Automobile Manufacturers Association Inc)
• JASO – Organisation japonaise de normalisation automobile (Japan Automobile Standards Organization)
• MSDS – fiche de données de sécurité (Material Safety Data Sheet)
• NLGI – Institut national des graisses lubrifiantes (National Lubricating Grease Institute)
• NMMA – Association nationale des constructeurs de bateaux (National Marine Manufacturers Association)
• PAO – Polyalphaoléfine (Polyalphaolefin)
• SAE – Société des ingénieurs de l’automobile (Society of Automotive Engineers)
• STLE – Société des tribologues et des ingénieurs en lubrification (Society of Tribologists and Lubrication Engineers)
• SUS or SSU – Secondes universelles Saybolt (Saybolt Universal Seconds)
• TAN –Indice d’acidité totale (Total Acid Number)
• TBN – Indice de base total (Total Base Number)
• VI – Indice de viscosité (Viscosity Index)
• VII – Indice de viscosité amélioré (Viscosity Index Improve)
• ZDP – Dithiophosphate de zinc (Zinc Dithiophosphate)

TERMES COMMUNS

Abrasion – Usure, meulage ou frottement par friction. L’abrasion est généralement due à la présence de matières étrangères telles que des saletés, des gravillons ou des particules métalliques dans le lubrifiant.

Viscosité absolue – Viscosité absolue – Le produit de la viscosité cinématique et de la densité.
Viscosité absolue (n) = Viscosité cinématique (y) x Densité (p).

Acide – Solution corrosive formée par la combinaison d’atomes d’hydrogène et d’oxygène avec des radicaux métalliques ou des métaux. Les solutions acides peuvent être neutralisées avec une base ou une solution alcaline.

Indice d’acidité – Mesure de la quantité de KOH nécessaire pour neutraliser tout ou partie de l’acidité d’un lubrifiant.

Additif – Matière ajoutée à un produit de base pour en modifier les propriétés, les caractéristiques ou les performances.

Adhésion – Propriété d’un lubrifiant qui lui permet de s’accrocher ou d’adhérer à une surface solide. L’usure se produit lorsque des surfaces entrent en contact, se soudent et se cisaillent.

Entraînement d’air – L’incorporation d’air sous forme de bulles dispersées dans un fluide. Fréquent lorsqu’une quantité inadéquate d’agent antimousse est ajoutée pour réduire la formation de mousse.

Température ambiante – Température de l’air entourant le point d’application.

Anhydre – Exempt d’eau.

Antimousse – Additif utilisé pour supprimer la tendance au moussage des lubrifiants en service. Une quantité inadéquate d’antimousse entraîne l’entraînement de l’air, ce qui entraîne également des problèmes de lubrification.

Antigel – Solution présente dans le système de refroidissement d’un moteur qui abaisse le point de congélation du liquide de refroidissement et augmente son point d’ébullition.

Antioxydant (inhibiteur d’oxydation) – Additif qui retarde l’oxydation des lubrifiants.

Anti-usure – Additifs qui forment de fines pellicules tenaces sur les pièces chargées pour empêcher le contact métal contre métal.

Viscosité apparente – Mesure de la viscosité d’un fluide non newtonien à une température et un cisaillement donnés. La viscosité est exprimée en unités de centipoise (cP).

Cendres – Dépôts métalliques formés dans la chambre de combustion et d’autres parties du moteur pendant le fonctionnement à haute température.

Cendres (sulfatées) – La teneur en cendres d’une huile, déterminée en carbonisant l’huile, en traitant le résidu avec de l’acide sulfurique et en l’évaporant à sec. Exprimée en % de la masse.

• ACRONYMSACEA – Association des constructeurs Européen d’automobiles
• AGMA –  Association américaine des fabricants d’engrenages
• API – Institut américain du pétrole
• ASLE – Société américaine des ingénieurs en lubrification (American Society of Lubrication Engineers)
• ASME – Société américaine des ingénieurs en mécanique (American Society of Mechanical Engineers)
• ASTM – température de pompage limite (American Society for Testing and MaterialsBPT – Borderline Pumping Temperature)
• BTU – Conseil des ressources atmosphériques de Californie (British Thermal UnitCARB – California Air Resources Board)
• CCS – simulateur de démarrage à froid (Cold Crank Simulator)
• CEC – Conseil européen de coordination pour les énergies renouvelables.
• CMA – Association des fabricants de produits chimiques (Chemical Manufacturers Association)
• cP – CentiPoise
• cSt – CentiStoke
• COC – Cleveland Open Cup
• DIN – Deutsche Industrie Norm
• EGR – Recirculation des gaz d’échappement (Exhaust Gas Recirculation)
• EHD or EHL – Lubrification élastohydrodynamique (Elastohydrodynamic Lubrication)
• EMA – Association des constructeurs de moteurs (Engine Manufacturers Association)
• EP – Extrême pression (Extreme Pressure)
• ILSAC – Comité international de normalisation et d’homologation des lubrifiants (International Lubricant Standardization and Approval Committee)
• ISO – Organisation internationale de normalisation (International Organization for Standardization)
• JAMA – Association des constructeurs japonais d’automobiles Inc (Japanese Automobile Manufacturers Association Inc)
• JASO – Organisation japonaise de normalisation automobile (Japan Automobile Standards Organization)
• MSDS – fiche de données de sécurité (Material Safety Data Sheet)
• NLGI – Institut national des graisses lubrifiantes (National Lubricating Grease Institute)
• NMMA – Association nationale des constructeurs de bateaux (National Marine Manufacturers Association)
• PAO – Polyalphaoléfine (Polyalphaolefin)
• SAE – Société des ingénieurs de l’automobile (Society of Automotive Engineers)
• STLE – Société des tribologues et des ingénieurs en lubrification (Society of Tribologists and Lubrication Engineers)
• SUS or SSU – Secondes universelles Saybolt (Saybolt Universal Seconds)
• TAN –Indice d’acidité totale (Total Acid Number)
• TBN – Indice de base total (Total Base Number)
• VI – Indice de viscosité (Viscosity Index)
• VII – Indice de viscosité amélioré (Viscosity Index Improve)
• ZDP – Dithiophosphate de zinc (Zinc Dithiophosphate)

TERMES COMMUNS

Abrasion – Usure, meulage ou frottement par friction. L’abrasion est généralement due à la présence de matières étrangères telles que des saletés, des gravillons ou des particules métalliques dans le lubrifiant.

Viscosité absolue – Viscosité absolue – Le produit de la viscosité cinématique et de la densité.
Viscosité absolue (n) = Viscosité cinématique (y) x Densité (p).

Acide – Solution corrosive formée par la combinaison d’atomes d’hydrogène et d’oxygène avec des radicaux métalliques ou des métaux. Les solutions acides peuvent être neutralisées avec une base ou une solution alcaline.

Indice d’acidité – Mesure de la quantité de KOH nécessaire pour neutraliser tout ou partie de l’acidité d’un lubrifiant.

Additif – Matière ajoutée à un produit de base pour en modifier les propriétés, les caractéristiques ou les performances.

Adhésion – Propriété d’un lubrifiant qui lui permet de s’accrocher ou d’adhérer à une surface solide. L’usure se produit lorsque des surfaces entrent en contact, se soudent et se cisaillent.

Entraînement d’air – L’incorporation d’air sous forme de bulles dispersées dans un fluide. Fréquent lorsqu’une quantité inadéquate d’agent antimousse est ajoutée pour réduire la formation de mousse.

Température ambiante – Température de l’air entourant le point d’application.

Anhydre – Exempt d’eau.

Antimousse – Additif utilisé pour supprimer la tendance au moussage des lubrifiants en service. Une quantité inadéquate d’antimousse entraîne l’entraînement de l’air, ce qui entraîne également des problèmes de lubrification.

Antigel – Solution présente dans le système de refroidissement d’un moteur qui abaisse le point de congélation du liquide de refroidissement et augmente son point d’ébullition.

Antioxydant (inhibiteur d’oxydation) – Additif qui retarde l’oxydation des lubrifiants.

Anti-usure – Additifs qui forment de fines pellicules tenaces sur les pièces chargées pour empêcher le contact métal contre métal.

Viscosité apparente – Mesure de la viscosité d’un fluide non newtonien à une température et un cisaillement donnés. La viscosité est exprimée en unités de centipoise (cP).

Cendres – Dépôts métalliques formés dans la chambre de combustion et d’autres parties du moteur pendant le fonctionnement à haute température.

Cendres (sulfatées) – La teneur en cendres d’une huile, déterminée en carbonisant l’huile, en traitant le résidu avec de l’acide sulfurique et en l’évaporant à sec. Exprimée en % de la masse.

Roulement à billes – Catégorie de roulement dans laquelle la surface mobile est séparée de la surface fixe par des éléments en forme de billes.

Bases – Composés qui réagissent avec les acides pour former des sels plus de l’eau. Les alcalins sont des bases hydrosolubles utilisées dans le raffinage du pétrole pour éliminer les impuretés acides. Les bases solubles dans l’huile sont incluses dans les additifs des huiles lubrifiantes pour neutraliser les acides formés pendant la combustion du carburant ou l’oxydation du lubrifiant.

Stock de base – Le fluide de base, généralement une fraction de pétrole raffiné ou un matériau synthétique sélectionné, dans lequel les additifs sont mélangés pour produire des lubrifiants finis.

Nombre de base – La quantité d’acide nécessaire pour neutraliser tout ou partie de la basicité d’un lubrifiant.

Bearing – Palier – Objet qui supporte le poids et réduit le frottement en permettant à une surface de tourner ou de glisser lorsqu’elle est soumise à une charge.

Biodegradable Biodégradable – Capacité d’un matériau à être décomposé, dans des paramètres donnés de temps et d’environnement, par des bactéries naturelles en substances simples, qui ne nuisent pas à l’environnement.

Bleeding – Purge – Séparation du lubrifiant liquide d’une graisse.

Blow-by – Passage du carburant non brûlé et des gaz de combustion le long des segments de piston des moteurs à combustion interne, entraînant la dilution du carburant et la contamination de l’huile du carter.

Boundary Lubrication –Lubrification limite – Lubrification entre deux surfaces de frottement sans le développement d’un film lubrifiant fluide complet. Elle se produit sous des charges élevées et nécessite l’utilisation d’additifs anti-usure ou extrême-pression pour empêcher le contact métal contre métal.

Brinelling – Denture causée par l’impact d’un composant de roulement contre un autre à l’arrêt.

Filtration par dérivation(By-Pass Filtration) – Système de filtration dans lequel seule une partie du débit total d’un système de circulation de fluide passe à travers un filtre à tout moment ou dans lequel un filtre ayant sa propre pompe de circulation fonctionne en parallèle au débit principal.

Carbon Residue – Résidu de carbone – Matière cokéfiée restant après qu’une huile ait été soumise à des températures élevées.

Cavitation – Cavitation – Formation et effondrement de bulles de vapeur dans un liquide.

Centipoise (cP) – Unité de mesure de la viscosité apparente.

Centistoke (cSt) – Unité de mesure de la viscosité cinématique.

Cetane Index – Une valeur calculée à partir des propriétés physiques d’un carburant diesel pour prédire son indice de cétane.

Cetane Number – Mesure de la qualité d’allumage d’un carburant diesel. Plus l’indice de cétane est élevé, plus un moteur à injection directe et à grande vitesse démarre facilement, et moins il y a de fumée blanche et de cognement après le démarrage.

Améliorant de l’indice de cétane – Un additif qui augmente l’indice de cétane d’un carburant tout en améliorant l’efficacité de la combustion et en augmentant la puissance dans un moteur diesel.

Point d’écoulement (Channel Point ) – Voir point d’écoulement. Lorsque vous réduisez la température d’une huile vers le point d’écoulement, vous atteignez un point où vous pouvez passer votre doigt dans une huile sans qu’elle ne se remplisse dans la tranchée que vous laissez derrière vous. Exemple : l’engrenage de la partie arrière d’une voiture. Bien que les engrenages puissent bouger, l’huile pour engrenages ne retournera pas dans l’engrenage pour le lubrifier facilement.

Stabilité chimique (Chemical Stability) – La tendance d’une substance ou d’un mélange à résister aux changements chimiques.

Cleveland Open Cup (C.O.C.) – An apparatus used to determine the flash and fire points of petroleum products other than fuel oils and those having an open cup flash below 79C/175F.

Cloud Point – The temperature at which a cloud of wax crystals appears when a lubricant or distillate fuel is cooled under standard conditions. Indicates the tendency of the material to plug filters or small orifices under cold weather conditions.

Coefficient of Friction – Number obtained by dividing the frictional force resisting motion between two bodies (F) by the normal force pressing the bodies together (L). m = F L

Cohesion – That property of a substance that causes it to resist being pulled apart by mechanical means.

Cold Cranking Simulator (C.C.S.) – An intermediate shear rate viscometer that predicts the ability of an oil to permit a satisfactory cranking speed to be developed in a cold engine.

Combustion Chamber – The space between the piston and cylinder head in an internal combustion engine where the charge of fuel plus air is burned to produce power.

Compatibility – A lubricants ability to be mixed with another lubricant without detriment to either lubricant. Also, the ability to come into contact with other components or materials without detrimental effects.

Compound – Substance formed by the combination of two or more elements with differing physical and chemical properties than the combining elements.

Compression Ignition – Ignition of fuel by the heat generated in compressing the air charge, as in the diesel engine.

Compression Ratio – The ratio of the volume of combustion space at the bottom dead center to that at top dead center, in an internal combustion engine.

Consistency – The degree to which a semi-solid material such as grease resists deformation.

Contaminant – Any material that is unwanted or adversely affects the fluid power system and/or its components.

Coolant – Fluid used to remove heat. Commonly found in an engines cooling system.

Copper Strip Corrosion – Qualitative measure of the tendency of a liquid to corrode pure copper.

Corrosion – Destruction of a metal by chemical or electo-chemical reaction with its environment.

Corrosion Inhibitor – Additive that protects lubricated metal surfaces from chemical attack by water or other contaminates.

Cracking – Refining process in which large molecules are broken down into smaller molecules. Cracking takes place to some extent whenever high molecular material is heated strongly, but can be increased by catalysts.

Crankcase – The housing in which the crankshaft and many other parts of the engine operate. On a two-cycle engine, the area in which the fuel/oil mixture is drawn before being transferred to the cylinder.

Crankcase Dilution – When unburned fuel finds its way past the piston rings into the crankcase oil, where it dilutes or thins out the engine lubricating oil.

Crude Oil – Naturally occurring petroleum, before any refining or treatment.

Demulsibility – The measure of a fluids ability to separate from water.

Density – Mass per unit of volume.

Detergent – Additif permettant de maintenir les pièces du moteur propres. Dans les formulations d’huile moteur, les détergents les plus couramment utilisés sont des savons métalliques avec une réserve de basicité pour neutraliser les acides formés lors de la combustion.

Detonation – Uncontrolled burning of the last portion (end gas) of the air/fuel mixture in the cylinder of a spark-ignition engine. Also known as knock or ping.

Differential – Set of gears that transfers the power from the drive shaft to the drive wheels and allows those wheels to turn at different speeds.

Dispersant – Additive that helps keep solid contaminants in crankcase oil in colloidal suspension, preventing sludge and varnish deposits on engine parts. Usually nonmetallic (ashless), and used in conjunction with detergents.

Distillation – Separation of a mixture of liquids with different boiling points by progressively raising the temperature. In a refinery distillation unit the temperature rises continuously from the top to the bottom of the column and different fractions or cuts are drawn off at different heights.

Distillation Test – The basic test used to characterize the volatility of a gasoline or distillate fuel.

Drag – Resistance to movement caused by oil viscosity.

Dropping Point – Temperature at which a grease passes from a semi-solid to a liquid state under specified test conditions.

Drum – A cylindrical container that holds 55 gallons of oil or approximately 400 pounds of grease type products. There are also half-size drums that hold approximately 30 gallons of oil.

Dynamic Viscosity – Viscosity of a liquid as measured in a rotational instrument, as distinct from the kinematic viscosity where the liquid falls through a capillary tube under its own weight.

E.G.R. (Exhaust Gas Recirculation) Valve – System to reduce automotive emission of nitrogen oxides (Nox). It routes exhaust gases into the intake manifold where they dilute the air/fuel mixture and reduce peak combustion temperatures, thereby reducing the tendency for Nox to form.

Elastohydrodynamic Lubrication (EHD or EHL) – Lubrication characterized by high unit loads and high speeds in rolling elements where the mating parts deform elastically due to the incompressibility of the lubricant film under very high pressure.

Elastomer – A rubbery type of material.

Emissions – Term used generically to refer to the various components of the engines exhaust.

Emulsifier – Substance used to promote or aid the formation of a stable mixture, or emulsion of oil & water.

Emulsion – Mixture of two liquids, which are not soluble with each other, such as oil and water.

Engine Deposits – Hard or persistent accumulation of sludge, varnish and carbonaceous residues due to blow-by of unburned and partially burned fuel, or the partial breakdown of the crankcase lubricant. Water from the condensation of combustion products, glycol, carbon, residues from fuel or lubricating oil additives, dust and metal particles also contribute.

EP (Extreme Pressure) – Lubrication regime where surfaces are sliding against each other under heavy load. The expression was coined for the condition present in hypoid gears in automotive rear axles.

EP (Extreme Pressure) Lubricants – Lubricants that impart to rubbing surfaces the ability of carrying greater loads than would be possible with ordinary lubricants without excessive wear or damage.

Erosion – The wearing away of a surface by an impinging fluid or solid

Ester – An organic compound formed by the reaction of an acid (organic or inorganic) with an alcohol.

Éthanol – Alcool éthylique formé principalement par fermentation. (boissons alcoolisées, composant du gasohol). L’éthanol peut être produit industriellement à partir de la pétrochimie par hydratation de l’éthylène, et par fermentation alcoolique de levures ou de cellulose. Le procédé le plus économique dépend principalement du marché pétrolier.

Ethylene Glycol – A colorless, syrupy liquid, used as an antifreeze in cooling and heating systems.

Perte par évaporation (volatilité) – La perte d’une partie d’un lubrifiant due à la volatilisation.

Fillers – A term normally used to denote something non-chemical added to an oil or grease, i.e., moly, graphite, zinc oxide.

Film Strength – The ability of a lubricant film to withstand the effects of speed, temperature and load without breaking down.

Filter – Any device or porous substance used for cleaning and removing suspended matter from a gas or fluid.

Fire Point – The temperature where a lubricant, when subjected to a source of ignition or flame, ignites & continues to burn.

Fire Resistant Fluid – A fluid, difficult to ignite, that shows little tendency to propagate flame.

Flash Point (C.O.C.) – The temperature to which a combustible liquid must be heated to give off substantial vapor to form a momentarily flammable mixture with air when a small flame is applied under specific conditions.

Fluid – Liquid, gas or combination thereof.

Fluid Friction – Occurs between the molecules of a gas or liquid in motion, and is expressed as shear stress. Unlike solid friction, fluid friction varies with speed and area.

Fluid Power – Energy transmitted and controlled through use of a pressurized fluid within an enclosed circuit.

Foam – An agglomeration of gas bubbles separated from each other by a thin liquid film. If an oil is said to not foam, the small air bubbles will quickly combine, become larger bubbles, and then break to vent to the atmosphere. If this action occurs slowly, the oil is said to foam.

Four Ball Test – Machine used to evaluate a lubricants antiwear qualities, frictional characteristics, or load carrying capabilities. There are four steel -inch balls. Three of the balls are clamped together in a cup filled with lubricant while the fourth ball is rotated against them. Two test procedures are based on this same principle the Four Ball EP Test (ASTM D-2596) and Four Ball Wear Test (ASTM D-2266).

Four Stroke Engine – An internal combustion engine that requires two revolutions of the crankshaft to complete all four cycles.

Fretting – Wear resulting from small amplitude motion between two surfaces; may produce red or black oxide.

Friction – Resistance to motion of one object over another. Friction depends on the smoothness of the contacting surfaces, as well as the force with which they are pressed together.

Fuel Dilution – The amount of unburned fuel present in the lubricant. This test will indicate problems such as fuel line, injector, carburetor and pump leaks. Fuel dilution is accurate down to less than 0.5%.

Full Film Lubrication – Complete separation of mated surfaces. No metal-to-metal contact.

Full-Flow Filtration – A system of filtration in which the total flow of a circulating fluid system passes through a filter prior to component delivery.

Gears – Toothed machine parts for transmitting power from one shaft to another.

Gravity – The mass/volume relationship of lubricants used in determining volume requirements for specific mass of products (packaging).

Grease – Lubricant composed of an oil or oils thickened with a soap, soaps or other thickener to a semi-solid consistency.

Gum – A rubber like, sticky deposit black or dark brown in color resulting from the oxidation of lubricating oils from unstable constituents in gasoline, which deposit during storage or use.

High Temperature High Shear Rate Viscosity (HTHS) – A measure of a fluids resistance to flow under conditions resembling highly-loaded journal bearings in fired internal combustion engines, typically 1 million s-1 at 150oC.

Horsepower – A measurement of an engines power, equal to 550 foot pounds of torque per second.

Hydrocarbons – Compounds of hydrogen & carbon of which petroleum products are typical examples. Also known as organic compounds.

Hydrodynamic Lubrication – The formation of a continuous lubricating fluid film between mating surfaces of sufficient pressure to prevent contact

Hydro finishing – A process for treating raw extracted base stocks with hydrogen to saturate them for improved stability.

Hydrolytic Stability – Ability of additives and certain synthetic lubricants to resist chemical decomposition (hydrolysis) in the presence of water.

Hypoid Gear Lubricant – A gear lubricant having extreme pressure characteristics for use in hypoid type gears (as in the differential of an automobile).

Incompatibility – When a mixture of two or more substances shows physical properties or service performance characteristics, which are inherently inferior to those of either of the individual products before mixing.

Inhibitor – Additive that improves the performance of a petroleum product by controlling undesirable chemical reactions, i.e., oxidation inhibitor, rust inhibitor, etc.

Insolubles – Contaminates found in used oils due to dust, dirt, wear particles or oxidation products.

Journal – Part of shaft or axle that rotates or angularly oscillates in or against a bearing or about which a bearing rotates or angularly oscillates.

Keg – Container which would typically hold 16 gallons of oil or approximately 120 pounds of a grease-type product. Also called a quarter drum.

Kinematic Viscosity – Measure of a fluids resistance to flow under gravity at a specific temperature (usually 40C or 100C).

Lubrication – Control of friction and wear by the introduction of a friction reducing film between moving surfaces in contact. May be a fluid, solid or plastic substance.

Material Safety Data Sheet (MSDS) – Vital information regarding the safe handling and storage of a product.

Micron – A millionth of a meter, or 0.0000394 inch.

Mineral Oil – Term applied to a wide range of products that is typically used when referring to petroleum-based lubricants.

Mini Rotary Viscometer – An instrument used to measure the borderline pumping temperature (BPT) of engine oils from 0C to -40C. BPT is the lowest temperature at which engine oil can be supplied in adequate amounts to the oil pump inlet.

Multi-viscosity/Multi Grade Oil – Engine or gear oil that meets the requirements of more than one SAE viscosity grade classification, and that can be used over a wider temperature range than a single grade oil.

Naphthenic – A type of petroleum fluid derived from naphthenic crude oil, containing a high proportion of closed-ring methylene groups.

Neutralization Number – A measure of the acidity or alkalinity of an oil.

Newtonian Flow – Occurs in a liquid system where the rate of shear is directly proportional to the shearing force, as with straight grade oils which do not contain polymeric viscosity modifier. When rate of shear is not directly proportional to the shearing force, flow is non-Newtonian, as it is with oils containing viscosity modifiers.

Nitration – Process where nitrogen oxides attack petroleum fluids at high temperatures, often resulting in viscosity increase and deposit formation. Nitration only occurs in applications where fuel is used.

NLGI – National Lubricating Grease Institute, an industry group that monitors grease and sets penetration standards for grading greases.

NLGI Number – A scale for comparing the consistency (hardness) range of greases.

Octane Number – A measure of a fuels ability to prevent detonation in a spark-ignition engine.

Organic Acid – An organic compound, with acid properties, obtained from organic substances such as animal, vegetable and mineral oils, i.e., a fatty acid.

Oxidation – Occurs when oxygen attacks fluids. The process is accelerated by heat, light, metal catalysts and the presence of water, acids, or solid contaminants. It leads to increased viscosity and deposit formation.

Oxidation Inhibitor – Substance added in small quantities to an oil product to increase its oxidation resistance, thereby lengthening its service or storage life. Also called an antioxidant.

Oxidation Stability – Resistance of an oil product to oxidation and, therefore, a measure of its potential service or storage life.

Oxygenated Fuels – Fuels for internal combustion engines that contain oxygen combined in the molecule, e.g., alcohols, ethers and esters. Term also applies to blends of gasoline with oxygenates, e.g., Gasohol, which contains 10% by volume of anhydrous ethanol in unleaded gasoline.

Paraffin – Hydrocarbons belonging to the series starting with methane (CH4). Paraffins are saturated with respect to hydrogen. High molecular weight paraffins are solid such as paraffin wax.

Particle – A minute piece of matter with observable length, width and thickness, usually measured in micrometers.

PCV (Positive Crankcase Ventilation) Valve – An emissions control device that allows gases from the crankcase to be reintroduced into the intake.

Penetration – A test in which a cone is dropped into a grease sample to measure the penetration or how hard or soft the grease is at room temperatures. The cone penetrates farther in a soft grease and therefore has a higher penetration number. This penetration relates to an NLGI number. A number 0 grease is called an NLGI 0 grade and will be softer than an NLGI 1 or 2 grade.

pH – A measure of acidity or alkalinity. Values of pH run from 0-14; 7 indicating neutrality, numbers less than 7 indicate increasing acidity, and numbers greater than 7 indicate increasing alkalinity.

Pitting – Surface cavities, may be related to fatigue, overload or corrosion.

Pneumatics – Engineering science pertaining to gaseous pressure and flow.

Poise – Unit of viscosity, defined by the shear stress required to move one layer of fluid along another over a total thickness of one centimeter at a velocity of one centimeter per second. This viscosity is independent of fluid density, and directly related to flow resistance.

Polishing (bore) – Excessive smoothing of the surface finish of the cylinder bore or cylinder liner in an engine to a mirror-like appearance, resulting in depreciation of ring sealing and oil consumption performance.

Polymerization – Chemical combination of similar type molecules to form larger molecules.

Pour Point – An indicator of the ability of an oil or distillate fuel to flow at cool operating temperatures. It is the lowest temperature at which the fluid will flow when cooled under prescribed conditions.

Pour Point Depressant – Additive used to lower the pour point or lower the temperature fluidity of a petroleum product.

Preignition – Ignition of the fuel/air mixture in a gasoline engine before the spark plug fires. Often caused by incandescent fuel or lubricant deposits in the combustion chamber, it wastes power and may damage the engine.

Propylene Glycol – A non-toxic liquid used as a coolant/antifreeze in cooling and heating systems.

Pumpability – The low temperature, low shear stress-shear rate viscosity characteristics of an oil that permit satisfactory flow to and from the engine oil pump and subsequent lubrication of moving components.

Refining – Series of processes to convert crude oil and its fractions into finished petroleum products, which may include thermal cracking, catalytic cracking, polymerization, alkylation, reforming, hydrocracking, hydrofoaming, hydrogenation, hydrogen treating, Hydrofining, solvent extraction, dewaxing, de-oiling, acid treating, clay filtration, deasphalting, etc.

Re-refining – A process of reclaiming used lubricant oils and restoring them to a condition similar to that of virgin stocks by filtration, clay adsorption or more elaborate methods.

Ring Sticking – Freezing of a piston ring in its groove in a piston engine or reciprocating compressor due to heavy deposits in the piston ring zone.

Rust – Slow oxidation of iron.

Rust Preventative – Compound for coating iron surfaces with a film that protects against rust. Commonly used to preserve equipment in storage.

SAE Grade – Numbers applied to automotive lubricants to indicate their viscosity range.

Saybolt, Saybolt Universal Seconds, SUS, or SSU – The most common viscosity measurement prior to the international acceptance of centistokes, SUS measurements are now obsolete. To convert measurements from SUS at 100F to an approximate value in cSt at 40C (ISO viscosity grade), divide the SUS value by 5.

Scoring – Scratches on mechanical parts in the direction of motion caused by abrasive contaminants.

Scuffing – Abnormal engine wear due to localized welding and fracture. It can be prevented through the use of antiwear, extreme-pressure and friction modifier additives. See adhesion.

Semi Fluid – Any substance having attributes of both a liquid and a solid. Similar to semi solid but being more closely related to a liquid than a solid.

Shearing – Relative slipping or sliding between one part of a substance and an adjacent part.

Shear Stability – Ability of a lubricant to withstand shearing forces without being degraded to lower viscosity or consistency.

Sludge – A thick, dark residue, normally of mayonnaise consistency, that accumulates on nonmoving engine interior surfaces. Generally removable by wiping unless baked into a carbonaceous consistency, its formation is associated with insolubles overloading the lubricant.

Solid – Any substance having definite shape that it does not readily relinquish. More generally, any substance in which the force required to produce a deformation depends upon the magnitude of the deformation rather than the rate of deformation.

Stoichiometric – Ratio of fuel to air where the exact proportions for complete reaction of both, with none left over, are present.

Stoke (St) – Kinematic measurement of a fluids resistance to flow defined by the ratio of the fluids dynamic viscosity to density.

Supercharger – A device for increasing the pressure and hence the mass of air and fuel burned on each firing stroke. Driven by the crankshaft; therefore, displacement is fixed and directly related to engine RPMs.

Surface Tension – The contractile surface force of a liquid by which it tends to assume a spherical form and to present the least possible surface. It is expressed in dyne/cm or ergs/cm.

Synthetic Lubricant – Fluid made by chemically reacting materials to produce a lube with a specific chemical composition, which has planned, and predictable properties.

Thermally Stable – Ability to withstand temperatures without decomposing. Not to be confused with oxidation stability where oxygen must be present and oxidation rather than decomposition.

Thickener – The metallic soap or other material used to combine with oil or other lubricating fluid to make a grease.

Torque – The twisting force with which the engines crankshaft actually rotates, measured in foot-pounds.

Total Acid Number (TAN) – The quantity of base, expressed in milligrams, that is required to neutralize all acidic constituents present in one gram of sample.

Total Base Number (TBN) – The quantity of acid, expressed in terms of the number of milligrams that is required to neutralize all basic constituents present in one-gram sample.

Total Solids – The total amount of solids contamination, both suspended and non-suspended present in the lubricant. This test is indicative of carburetion problems (too rich or too lean), if the oil filter has reached the saturation point and is no longer able to remove contamination from the system, and if the air intake system is functioning properly and allowing enough air into the unit for complete burn to take place.

Tribology – Science of the interactions between surfaces moving relative to each other, including the study of lubrication, friction and wear.

Turbine – A device consisting of blades attached to a disc or rotor, which converts flow into rotary action.

Turbocharger – A device for increasing the pressure and hence the mass of air and fuel burned on each firing stroke. A turbine of exhaust gases drives a compressor; therefore, efficiency is variable and related to exhaust pressure.

Vapor Lock – Condition wherein the fuel boils in the fuel system forming bubbles that retard or stop the flow of fuel to the engine.

Varnish – A thin, insoluble, non-wipeable film occurring on interior engine parts.

Viscosity – Measure of a fluids resistance to flow.

Viscosity Index (V.I.) – Relationship of viscosity to temperature of a fluid. High viscosity index fluids tend to display less change in viscosity with temperature than low viscosity index fluids.

Viscosity Index Improver (V.I.I.) – Additive to improve or increase the viscosity index. A VI improver increases an oils resistance to thinning as it is heated. It is commonly used in multi-viscosity or multigrade oils. Since a VI improver increases the viscosity as well as the viscosity index, it must be taken into consideration when formulating oil. (Example: taking an oil in the SAE 30 range, adding a VI improver could give an oil like a SAE 40)

Viscosity Modifier – See V.I.I. Additive, usually a high molecular weight polymer that reduces the tendency of an oils viscosity to change with temperature.

Wear – Damage resulting from the removal of materials from surfaces in relative motion.

Zinc (ZDP) – Commonly used name for zinc dithiophosphate, an antiwear/oxidation inhibitor chemical

Bases – Compounds that react with acids to form salts plus water. Alkalis are water-soluble bases used in petroleum refining to remove acidic impurities. Oil soluble bases are included in lubricating oil additives to neutralize acids formed during the combustion of fuel or oxidation of the lubricant.

Base Stock – The base fluid, usually a refined petroleum fraction or a selected synthetic material, into which additives are blended to produce finished lubricants.

Base Number – The amount of acid needed to neutralize all or part of a lubricants basicity.

Bearing – An object that supports weight and reduces friction by allowing a surface to rotate or slide when under load.

Biodegradable – Ability of a material can be broken down, within given parameters of time and environment, by naturally occurring bacteria into simple substances, which do not harm the environment.

Bleeding – Separation of liquid lubricant from a grease.

Blow-by – Passage of unburned fuel and combustion gases past the piston rings of internal combustion engines, resulting in fuel dilution and contamination of the crankcase oil.

Boundary Lubrication – Lubrication between two rubbing surfaces without the development of a full fluid lubricating film. It occurs under high loads and requires the use of antiwear or extreme-pressure additives to prevent metal-to metal contact.

Brinelling – Denting caused by impact of one bearing component against another while stationary.

By-Pass Filtration – Système de filtration dans lequel seule une partie du débit total d’un système de circulation de fluide passe à travers un filtre à tout moment ou dans lequel un filtre ayant sa propre pompe de circulation fonctionne en parallèle avec le débit principal.

Carbon Residue – Coked material remaining after an oil has been subjected to high temperatures.

Cavitation – The formation and collapse of vapor bubbles within a liquid.

Centipoise (cP) – Unit of measure for apparent viscosity.

Centistoke (cSt) – Unit of measure for Kinematic Viscosity.

Cetane Index – A value calculated from the physical properties of a diesel fuel to predict its Cetane Number.

Cetane Number – Measure of ignition quality of a diesel fuel. The higher the Cetane Number, the easier a high-speed, direct injection engine will start, and the less white smoking and diesel knock after start up.

Cetane Number Improver – An additive that boosts the Cetane Number of a fuel while improving combustion efficiency and increasing power in a diesel engine.

Channel Point – See pour point. As you reduce the temperature of an oil toward the pour point, you reach a point where you can run your finger through an oil and it will not fill in the trench you leave behind. Example: the gearing in the rear end of a car. Although the gears might move, the gear oil will not flow back into the gear to lubricate it readily.

Chemical Stability – The tendency of a substance or mixture to resist chemical change.

Cleveland Open Cup (C.O.C.) – An apparatus used to determine the flash and fire points of petroleum products other than fuel oils and those having an open cup flash below 79C/175F.

Cloud Point – The temperature at which a cloud of wax crystals appears when a lubricant or distillate fuel is cooled under standard conditions. Indicates the tendency of the material to plug filters or small orifices under cold weather conditions.

Coefficient of Friction – Number obtained by dividing the frictional force resisting motion between two bodies (F) by the normal force pressing the bodies together (L). m = F L

Cohesion – That property of a substance that causes it to resist being pulled apart by mechanical means.

Cold Cranking Simulator (C.C.S.) – An intermediate shear rate viscometer that predicts the ability of an oil to permit a satisfactory cranking speed to be developed in a cold engine.

Combustion Chamber – The space between the piston and cylinder head in an internal combustion engine where the charge of fuel plus air is burned to produce power.

Compatibility – A lubricants ability to be mixed with another lubricant without detriment to either lubricant. Also, the ability to come into contact with other components or materials without detrimental effects.

Compound – Substance formed by the combination of two or more elements with differing physical and chemical properties than the combining elements.

Compression Ignition – Ignition of fuel by the heat generated in compressing the air charge, as in the diesel engine.

Compression Ratio – The ratio of the volume of combustion space at the bottom dead center to that at top dead center, in an internal combustion engine.

Consistency – The degree to which a semi-solid material such as grease resists deformation.

Contaminant – Any material that is unwanted or adversely affects the fluid power system and/or its components.

Coolant – Fluid used to remove heat. Commonly found in an engines cooling system.

Copper Strip Corrosion – Qualitative measure of the tendency of a liquid to corrode pure copper.

Corrosion – Destruction of a metal by chemical or electo-chemical reaction with its environment.

Corrosion Inhibitor – Additive that protects lubricated metal surfaces from chemical attack by water or other contaminates.

Cracking – Refining process in which large molecules are broken down into smaller molecules. Cracking takes place to some extent whenever high molecular material is heated strongly, but can be increased by catalysts.

Crankcase – The housing in which the crankshaft and many other parts of the engine operate. On a two-cycle engine, the area in which the fuel/oil mixture is drawn before being transferred to the cylinder.

Crankcase Dilution – When unburned fuel finds its way past the piston rings into the crankcase oil, where it dilutes or thins out the engine lubricating oil.

Crude Oil – Naturally occurring petroleum, before any refining or treatment.

Demulsibility – The measure of a fluids ability to separate from water.

Density – Mass per unit of volume.

Detergent – Additif permettant de maintenir les pièces du moteur propres. Dans les formulations d’huile moteur, les détergents les plus couramment utilisés sont des savons métalliques avec une réserve de basicité pour neutraliser les acides formés lors de la combustion.

Detonation – Uncontrolled burning of the last portion (end gas) of the air/fuel mixture in the cylinder of a spark-ignition engine. Also known as knock or ping.

Differential – Set of gears that transfers the power from the drive shaft to the drive wheels and allows those wheels to turn at different speeds.

Dispersant – Additive that helps keep solid contaminants in crankcase oil in colloidal suspension, preventing sludge and varnish deposits on engine parts. Usually nonmetallic (ashless), and used in conjunction with detergents.

Distillation – Separation of a mixture of liquids with different boiling points by progressively raising the temperature. In a refinery distillation unit the temperature rises continuously from the top to the bottom of the column and different fractions or cuts are drawn off at different heights.

Distillation Test – The basic test used to characterize the volatility of a gasoline or distillate fuel.

Drag – Resistance to movement caused by oil viscosity.

Dropping Point – Temperature at which a grease passes from a semi-solid to a liquid state under specified test conditions.

Drum – A cylindrical container that holds 55 gallons of oil or approximately 400 pounds of grease type products. There are also half-size drums that hold approximately 30 gallons of oil.

Dynamic Viscosity – Viscosity of a liquid as measured in a rotational instrument, as distinct from the kinematic viscosity where the liquid falls through a capillary tube under its own weight.

E.G.R. (Exhaust Gas Recirculation) Valve – System to reduce automotive emission of nitrogen oxides (Nox). It routes exhaust gases into the intake manifold where they dilute the air/fuel mixture and reduce peak combustion temperatures, thereby reducing the tendency for Nox to form.

Elastohydrodynamic Lubrication (EHD or EHL) – Lubrication characterized by high unit loads and high speeds in rolling elements where the mating parts deform elastically due to the incompressibility of the lubricant film under very high pressure.

Elastomer – A rubbery type of material.

Emissions – Term used generically to refer to the various components of the engines exhaust.

Emulsifier – Substance used to promote or aid the formation of a stable mixture, or emulsion of oil & water.

Emulsion – Mixture of two liquids, which are not soluble with each other, such as oil and water.

Engine Deposits – Hard or persistent accumulation of sludge, varnish and carbonaceous residues due to blow-by of unburned and partially burned fuel, or the partial breakdown of the crankcase lubricant. Water from the condensation of combustion products, glycol, carbon, residues from fuel or lubricating oil additives, dust and metal particles also contribute.

EP (Extreme Pressure) – Lubrication regime where surfaces are sliding against each other under heavy load. The expression was coined for the condition present in hypoid gears in automotive rear axles.

EP (Extreme Pressure) Lubricants – Lubricants that impart to rubbing surfaces the ability of carrying greater loads than would be possible with ordinary lubricants without excessive wear or damage.

Erosion – The wearing away of a surface by an impinging fluid or solid

Ester – An organic compound formed by the reaction of an acid (organic or inorganic) with an alcohol.

Ethanol – L’alcool éthylique se forme principalement par fermentation. (boissons alcoolisées, composant du gasohol)

Evaporation Loss – The loss of a portion of a lubricant due to volatization.

Fillers – A term normally used to denote something non-chemical added to an oil or grease, i.e., moly, graphite, zinc oxide.

Film Strength – The ability of a lubricant film to withstand the effects of speed, temperature and load without breaking down.

Filter – Any device or porous substance used for cleaning and removing suspended matter from a gas or fluid.

Fire Point – The temperature where a lubricant, when subjected to a source of ignition or flame, ignites & continues to burn.

Fire Resistant Fluid – A fluid, difficult to ignite, that shows little tendency to propagate flame.

Flash Point (C.O.C.) – The temperature to which a combustible liquid must be heated to give off substantial vapor to form a momentarily flammable mixture with air when a small flame is applied under specific conditions.

Fluid – Liquid, gas or combination thereof.

Fluid Friction – Occurs between the molecules of a gas or liquid in motion, and is expressed as shear stress. Unlike solid friction, fluid friction varies with speed and area.

Fluid Power – Énergie transmise et contrôlée par l’utilisation d’un fluide sous pression dans un circuit fermé.

Foam – Agglomération de bulles de gaz séparées les unes des autres par un mince film liquide. Si l’on dit d’une huile qu’elle ne mousse pas, les petites bulles d’air se combinent rapidement, deviennent des bulles plus grosses, puis se brisent pour s’échapper dans l’atmosphère. Si cette action se produit lentement, on dit que l’huile mousse.

Four Ball Test –

Machine utilisée pour évaluer les qualités anti-usure, les caractéristiques de frottement ou les capacités de charge d’un lubrifiant. Il y a quatre billes d’acier d’un pouce. Trois des billes sont serrées ensemble dans une coupelle remplie de lubrifiant tandis que la quatrième bille est mise en rotation contre elles. Deux procédures d’essai sont basées sur ce même principe : le Four Ball EP Test (ASTM D-2596) et le Four Ball Wear Test (ASTM D-2266).

Four Stroke Engine – Un moteur à combustion interne qui nécessite deux révolutions du vilebrequin pour effectuer les quatre cycles.

Fretting – Usure résultant d’un mouvement de faible amplitude entre deux surfaces ; peut produire de l’oxyde rouge ou noir.

Friction – Résistance au mouvement d’un objet par rapport à un autre. Le frottement dépend de la douceur des surfaces en contact, ainsi que de la force avec laquelle elles sont pressées l’une contre l’autre.

Fuel Dilution – The amount of unburned fuel present in the lubricant. This test will indicate problems such as fuel line, injector, carburetor and pump leaks. Fuel dilution is accurate down to less than 0.5%.

Full Film Lubrication – Complete separation of mated surfaces. No metal-to-metal contact.

Full-Flow Filtration – A system of filtration in which the total flow of a circulating fluid system passes through a filter prior to component delivery.

Gears – Toothed machine parts for transmitting power from one shaft to another.

Gravity – The mass/volume relationship of lubricants used in determining volume requirements for specific mass of products (packaging).

Grease – Lubricant composed of an oil or oils thickened with a soap, soaps or other thickener to a semi-solid consistency.

Gum – A rubber like, sticky deposit black or dark brown in color resulting from the oxidation of lubricating oils from unstable constituents in gasoline, which deposit during storage or use.

High Temperature High Shear Rate Viscosity (HTHS) – A measure of a fluids resistance to flow under conditions resembling highly-loaded journal bearings in fired internal combustion engines, typically 1 million s-1 at 150oC.

Horsepower – A measurement of an engines power, equal to 550 foot pounds of torque per second.

Hydrocarbons – Compounds of hydrogen & carbon of which petroleum products are typical examples. Also known as organic compounds.

Hydrodynamic Lubrication – The formation of a continuous lubricating fluid film between mating surfaces of sufficient pressure to prevent contact

Hydro finishing – A process for treating raw extracted base stocks with hydrogen to saturate them for improved stability.

Hydrolytic Stability – Ability of additives and certain synthetic lubricants to resist chemical decomposition (hydrolysis) in the presence of water.

Hypoid Gear Lubricant – A gear lubricant having extreme pressure characteristics for use in hypoid type gears (as in the differential of an automobile).

Incompatibility – When a mixture of two or more substances shows physical properties or service performance characteristics, which are inherently inferior to those of either of the individual products before mixing.

Inhibitor – Additive that improves the performance of a petroleum product by controlling undesirable chemical reactions, i.e., oxidation inhibitor, rust inhibitor, etc.

Insolubles – Contaminates found in used oils due to dust, dirt, wear particles or oxidation products.

Journal – Part of shaft or axle that rotates or angularly oscillates in or against a bearing or about which a bearing rotates or angularly oscillates.

Keg – Container which would typically hold 16 gallons of oil or approximately 120 pounds of a grease-type product. Also called a quarter drum.

Kinematic Viscosity – Measure of a fluids resistance to flow under gravity at a specific temperature (usually 40C or 100C).

Lubrication – Control of friction and wear by the introduction of a friction reducing film between moving surfaces in contact. May be a fluid, solid or plastic substance.

Material Safety Data Sheet (MSDS) – Vital information regarding the safe handling and storage of a product.

Micron – A millionth of a meter, or 0.0000394 inch.

Mineral Oil – Term applied to a wide range of products that is typically used when referring to petroleum-based lubricants.

Mini Rotary Viscometer – An instrument used to measure the borderline pumping temperature (BPT) of engine oils from 0C to -40C. BPT is the lowest temperature at which engine oil can be supplied in adequate amounts to the oil pump inlet.

Multi-viscosity/Multi Grade Oil – Engine or gear oil that meets the requirements of more than one SAE viscosity grade classification, and that can be used over a wider temperature range than a single grade oil.

Naphthenic – A type of petroleum fluid derived from naphthenic crude oil, containing a high proportion of closed-ring methylene groups.

Neutralization Number – A measure of the acidity or alkalinity of an oil.

Newtonian Flow – Occurs in a liquid system where the rate of shear is directly proportional to the shearing force, as with straight grade oils which do not contain polymeric viscosity modifier. When rate of shear is not directly proportional to the shearing force, flow is non-Newtonian, as it is with oils containing viscosity modifiers.

Nitration – Process where nitrogen oxides attack petroleum fluids at high temperatures, often resulting in viscosity increase and deposit formation. Nitration only occurs in applications where fuel is used.

NLGI – National Lubricating Grease Institute, an industry group that monitors grease and sets penetration standards for grading greases.

NLGI Number – A scale for comparing the consistency (hardness) range of greases.

Octane Number – A measure of a fuels ability to prevent detonation in a spark-ignition engine.

Organic Acid – Composé organique, aux propriétés acides, obtenu à partir de substances organiques telles que les huiles animales, végétales et minérales, c’est-à-dire un acide gras.

Inhibiteur d’oxydation (Oxidation Inhibitor) – Substance ajoutée en petites quantités à un produit pétrolier pour augmenter sa résistance à l’oxydation, ce qui prolonge sa durée de vie ou de stockage. Également appelé antioxydant.

Oxidation Stability – Résistance d’un produit pétrolier à l’oxydation et, par conséquent, mesure de sa durée de vie ou de stockage potentielle.

Oxygenated Fuels – Carburants pour moteurs à combustion interne qui contiennent de l’oxygène combiné dans la molécule, par exemple, les alcools, les éthers et les esters. Le terme s’applique également aux mélanges d’essence avec des composés oxygénés, par exemple le Gasohol, qui contient 10 % en volume d’éthanol anhydre dans de l’essence sans plomb.

Paraffiine – Hydrocarbures appartenant à la série commençant par le méthane (CH4). Les paraffines sont saturées par rapport à l’hydrogène. Les paraffines de poids moléculaire élevé sont solides, comme la paraffine.

Particle –Un minuscule morceau de matière dont la longueur, la largeur et l’épaisseur sont observables, généralement mesurées en micromètres.

PCV (Positive Crankcase Ventilation) Valve – An emissions control device that allows gases from the crankcase to be reintroduced into the intake.

Penetration – A test in which a cone is dropped into a grease sample to measure the penetration or how hard or soft the grease is at room temperatures. The cone penetrates farther in a soft grease and therefore has a higher penetration number. This penetration relates to an NLGI number. A number 0 grease is called an NLGI 0 grade and will be softer than an NLGI 1 or 2 grade.

pH – A measure of acidity or alkalinity. Values of pH run from 0-14; 7 indicating neutrality, numbers less than 7 indicate increasing acidity, and numbers greater than 7 indicate increasing alkalinity.

Pitting – Surface cavities, may be related to fatigue, overload or corrosion.

Pneumatics – Engineering science pertaining to gaseous pressure and flow.

Poise – Unit of viscosity, defined by the shear stress required to move one layer of fluid along another over a total thickness of one centimeter at a velocity of one centimeter per second. This viscosity is independent of fluid density, and directly related to flow resistance.

Polishing (bore) – Excessive smoothing of the surface finish of the cylinder bore or cylinder liner in an engine to a mirror-like appearance, resulting in depreciation of ring sealing and oil consumption performance.

Polymerization – Chemical combination of similar type molecules to form larger molecules.

Pour Point – An indicator of the ability of an oil or distillate fuel to flow at cool operating temperatures. It is the lowest temperature at which the fluid will flow when cooled under prescribed conditions.

Pour Point Depressant – Additive used to lower the pour point or lower the temperature fluidity of a petroleum product.

Preignition – Ignition of the fuel/air mixture in a gasoline engine before the spark plug fires. Often caused by incandescent fuel or lubricant deposits in the combustion chamber, it wastes power and may damage the engine.

Propylene Glycol – A non-toxic liquid used as a coolant/antifreeze in cooling and heating systems.

Pumpability – The low temperature, low shear stress-shear rate viscosity characteristics of an oil that permit satisfactory flow to and from the engine oil pump and subsequent lubrication of moving components.

Refining – Series of processes to convert crude oil and its fractions into finished petroleum products, which may include thermal cracking, catalytic cracking, polymerization, alkylation, reforming, hydrocracking, hydrofoaming, hydrogenation, hydrogen treating, Hydrofining, solvent extraction, dewaxing, de-oiling, acid treating, clay filtration, deasphalting, etc.

Re-refining – A process of reclaiming used lubricant oils and restoring them to a condition similar to that of virgin stocks by filtration, clay adsorption or more elaborate methods.

Ring Sticking – Freezing of a piston ring in its groove in a piston engine or reciprocating compressor due to heavy deposits in the piston ring zone.

Rust – Slow oxidation of iron.

Rust Preventative – Compound for coating iron surfaces with a film that protects against rust. Commonly used to preserve equipment in storage.

SAE Grade – Numbers applied to automotive lubricants to indicate their viscosity range.

Saybolt, Saybolt Universal Seconds, SUS, or SSU – The most common viscosity measurement prior to the international acceptance of centistokes, SUS measurements are now obsolete. To convert measurements from SUS at 100F to an approximate value in cSt at 40C (ISO viscosity grade), divide the SUS value by 5.

Scoring – Scratches on mechanical parts in the direction of motion caused by abrasive contaminants.

Scuffing – Abnormal engine wear due to localized welding and fracture. It can be prevented through the use of antiwear, extreme-pressure and friction modifier additives. See adhesion.

Semi Fluid – Any substance having attributes of both a liquid and a solid. Similar to semi solid but being more closely related to a liquid than a solid.

Shearing – Relative slipping or sliding between one part of a substance and an adjacent part.

Shear Stability – Ability of a lubricant to withstand shearing forces without being degraded to lower viscosity or consistency.

Sludge – A thick, dark residue, normally of mayonnaise consistency, that accumulates on nonmoving engine interior surfaces. Generally removable by wiping unless baked into a carbonaceous consistency, its formation is associated with insolubles overloading the lubricant.

Solid – Any substance having definite shape that it does not readily relinquish. More generally, any substance in which the force required to produce a deformation depends upon the magnitude of the deformation rather than the rate of deformation.

Stoichiometric – Ratio of fuel to air where the exact proportions for complete reaction of both, with none left over, are present.

Stoke (St) – Kinematic measurement of a fluids resistance to flow defined by the ratio of the fluids dynamic viscosity to density.

Supercharger – A device for increasing the pressure and hence the mass of air and fuel burned on each firing stroke. Driven by the crankshaft; therefore, displacement is fixed and directly related to engine RPMs.

Surface Tension – The contractile surface force of a liquid by which it tends to assume a spherical form and to present the least possible surface. It is expressed in dyne/cm or ergs/cm.

Synthetic Lubricant – Fluid made by chemically reacting materials to produce a lube with a specific chemical composition, which has planned, and predictable properties.

Thermally Stable – Ability to withstand temperatures without decomposing. Not to be confused with oxidation stability where oxygen must be present and oxidation rather than decomposition.

Thickener – The metallic soap or other material used to combine with oil or other lubricating fluid to make a grease.

Torque – The twisting force with which the engines crankshaft actually rotates, measured in foot-pounds.

Total Acid Number (TAN) – The quantity of base, expressed in milligrams, that is required to neutralize all acidic constituents present in one gram of sample.

Total Base Number (TBN) – The quantity of acid, expressed in terms of the number of milligrams that is required to neutralize all basic constituents present in one-gram sample.

Total Solids – The total amount of solids contamination, both suspended and non-suspended present in the lubricant. This test is indicative of carburetion problems (too rich or too lean), if the oil filter has reached the saturation point and is no longer able to remove contamination from the system, and if the air intake system is functioning properly and allowing enough air into the unit for complete burn to take place.

Tribology – Science of the interactions between surfaces moving relative to each other, including the study of lubrication, friction and wear.

Turbine – A device consisting of blades attached to a disc or rotor, which converts flow into rotary action.

Turbocharger – A device for increasing the pressure and hence the mass of air and fuel burned on each firing stroke. A turbine of exhaust gases drives a compressor; therefore, efficiency is variable and related to exhaust pressure.

Vapor Lock – Condition wherein the fuel boils in the fuel system forming bubbles that retard or stop the flow of fuel to the engine.

Varnish – A thin, insoluble, non-wipeable film occurring on interior engine parts.

Viscosity – Measure of a fluids resistance to flow.

Viscosity Index (V.I.) – Relationship of viscosity to temperature of a fluid. High viscosity index fluids tend to display less change in viscosity with temperature than low viscosity index fluids.

Viscosity Index Improver (V.I.I.) – Additive to improve or increase the viscosity index. A VI improver increases an oils resistance to thinning as it is heated. It is commonly used in multi-viscosity or multigrade oils. Since a VI improver increases the viscosity as well as the viscosity index, it must be taken into consideration when formulating oil. (Example: taking an oil in the SAE 30 range, adding a VI improver could give an oil like a SAE 40)

Viscosity Modifier – See V.I.I. Additive, usually a high molecular weight polymer that reduces the tendency of an oils viscosity to change with temperature.

Wear – Damage resulting from the removal of materials from surfaces in relative motion.

Zinc (ZDP) – Commonly used name for zinc dithiophosphate, an antiwear/oxidation inhibitor chemical

Bases – Compounds that react with acids to form salts plus water. Alkalis are water-soluble bases used in petroleum refining to remove acidic impurities. Oil soluble bases are included in lubricating oil additives to neutralize acids formed during the combustion of fuel or oxidation of the lubricant.

Base Stock – The base fluid, usually a refined petroleum fraction or a selected synthetic material, into which additives are blended to produce finished lubricants.

Base Number – The amount of acid needed to neutralize all or part of a lubricants basicity.

Bearing – An object that supports weight and reduces friction by allowing a surface to rotate or slide when under load.

Biodegradable – Ability of a material can be broken down, within given parameters of time and environment, by naturally occurring bacteria into simple substances, which do not harm the environment.

Bleeding – Separation of liquid lubricant from a grease.

Blow-by – Passage of unburned fuel and combustion gases past the piston rings of internal combustion engines, resulting in fuel dilution and contamination of the crankcase oil.

Boundary Lubrication – Lubrication between two rubbing surfaces without the development of a full fluid lubricating film. It occurs under high loads and requires the use of antiwear or extreme-pressure additives to prevent metal-to metal contact.

Brinelling – Denting caused by impact of one bearing component against another while stationary.

By-Pass Filtration – A system of filtration in which only a portion of the total flow of a circulating fluid system passes through a filter at any instant or in which a filter having its own circulating pump operates in parallel to the main flow.

Carbon Residue – Coked material remaining after an oil has been subjected to high temperatures.

Cavitation – The formation and collapse of vapor bubbles within a liquid.

Centipoise (cP) – Unit of measure for apparent viscosity.

Centistoke (cSt) – Unit of measure for Kinematic Viscosity.

Cetane Index – A value calculated from the physical properties of a diesel fuel to predict its Cetane Number.

Cetane Number – Measure of ignition quality of a diesel fuel. The higher the Cetane Number, the easier a high-speed, direct injection engine will start, and the less white smoking and diesel knock after start up.

Cetane Number Improver – An additive that boosts the Cetane Number of a fuel while improving combustion efficiency and increasing power in a diesel engine.

Channel Point – See pour point. As you reduce the temperature of an oil toward the pour point, you reach a point where you can run your finger through an oil and it will not fill in the trench you leave behind. Example: the gearing in the rear end of a car. Although the gears might move, the gear oil will not flow back into the gear to lubricate it readily.

Chemical Stability – The tendency of a substance or mixture to resist chemical change.

Cleveland Open Cup (C.O.C.) – An apparatus used to determine the flash and fire points of petroleum products other than fuel oils and those having an open cup flash below 79C/175F.

Cloud Point – The temperature at which a cloud of wax crystals appears when a lubricant or distillate fuel is cooled under standard conditions. Indicates the tendency of the material to plug filters or small orifices under cold weather conditions.

Coefficient of Friction – Number obtained by dividing the frictional force resisting motion between two bodies (F) by the normal force pressing the bodies together (L). m = F L

Cohesion – That property of a substance that causes it to resist being pulled apart by mechanical means.

Cold Cranking Simulator (C.C.S.) – An intermediate shear rate viscometer that predicts the ability of an oil to permit a satisfactory cranking speed to be developed in a cold engine.

Combustion Chamber – The space between the piston and cylinder head in an internal combustion engine where the charge of fuel plus air is burned to produce power.

Compatibility – A lubricants ability to be mixed with another lubricant without detriment to either lubricant. Also, the ability to come into contact with other components or materials without detrimental effects.

Compound – Substance formed by the combination of two or more elements with differing physical and chemical properties than the combining elements.

Compression Ignition – Ignition of fuel by the heat generated in compressing the air charge, as in the diesel engine.

Compression Ratio – The ratio of the volume of combustion space at the bottom dead center to that at top dead center, in an internal combustion engine.

Consistency – The degree to which a semi-solid material such as grease resists deformation.

Contaminant – Any material that is unwanted or adversely affects the fluid power system and/or its components.

Coolant – Fluid used to remove heat. Commonly found in an engines cooling system.

Copper Strip Corrosion – Qualitative measure of the tendency of a liquid to corrode pure copper.

Corrosion – Destruction of a metal by chemical or electo-chemical reaction with its environment.

Corrosion Inhibitor – Additive that protects lubricated metal surfaces from chemical attack by water or other contaminates.

Cracking – Refining process in which large molecules are broken down into smaller molecules. Cracking takes place to some extent whenever high molecular material is heated strongly, but can be increased by catalysts.

Crankcase – The housing in which the crankshaft and many other parts of the engine operate. On a two-cycle engine, the area in which the fuel/oil mixture is drawn before being transferred to the cylinder.

Crankcase Dilution – When unburned fuel finds its way past the piston rings into the crankcase oil, where it dilutes or thins out the engine lubricating oil.

Crude Oil – Naturally occurring petroleum, before any refining or treatment.

Demulsibility – The measure of a fluids ability to separate from water.

Density – Mass per unit of volume.

Detergent – Additive to keep engine parts clean. In motor oil formulations, the most commonly used detergents are metallic soaps with a reserve of basicity to neutralize acids formed during combustion.

Detonation – Uncontrolled burning of the last portion (end gas) of the air/fuel mixture in the cylinder of a spark-ignition engine. Also known as knock or ping.

Differential – Set of gears that transfers the power from the drive shaft to the drive wheels and allows those wheels to turn at different speeds.

Dispersant – Additive that helps keep solid contaminants in crankcase oil in colloidal suspension, preventing sludge and varnish deposits on engine parts. Usually nonmetallic (ashless), and used in conjunction with detergents.

Distillation – Separation of a mixture of liquids with different boiling points by progressively raising the temperature. In a refinery distillation unit the temperature rises continuously from the top to the bottom of the column and different fractions or cuts are drawn off at different heights.

Distillation Test – The basic test used to characterize the volatility of a gasoline or distillate fuel.

Drag – Resistance to movement caused by oil viscosity.

Dropping Point – Temperature at which a grease passes from a semi-solid to a liquid state under specified test conditions.

Drum – A cylindrical container that holds 55 gallons of oil or approximately 400 pounds of grease type products. There are also half-size drums that hold approximately 30 gallons of oil.

Dynamic Viscosity – Viscosity of a liquid as measured in a rotational instrument, as distinct from the kinematic viscosity where the liquid falls through a capillary tube under its own weight.

E.G.R. (Exhaust Gas Recirculation) Valve – System to reduce automotive emission of nitrogen oxides (Nox). It routes exhaust gases into the intake manifold where they dilute the air/fuel mixture and reduce peak combustion temperatures, thereby reducing the tendency for Nox to form.

Elastohydrodynamic Lubrication (EHD or EHL) – Lubrication characterized by high unit loads and high speeds in rolling elements where the mating parts deform elastically due to the incompressibility of the lubricant film under very high pressure.

Elastomer – A rubbery type of material.

Emissions – Term used generically to refer to the various components of the engines exhaust.

Emulsifier – Substance used to promote or aid the formation of a stable mixture, or emulsion of oil & water.

Emulsion – Mixture of two liquids, which are not soluble with each other, such as oil and water.

Engine Deposits – Hard or persistent accumulation of sludge, varnish and carbonaceous residues due to blow-by of unburned and partially burned fuel, or the partial breakdown of the crankcase lubricant. Water from the condensation of combustion products, glycol, carbon, residues from fuel or lubricating oil additives, dust and metal particles also contribute.

EP (Extreme Pressure) – Lubrication regime where surfaces are sliding against each other under heavy load. The expression was coined for the condition present in hypoid gears in automotive rear axles.

EP (Extreme Pressure) Lubricants – Lubricants that impart to rubbing surfaces the ability of carrying greater loads than would be possible with ordinary lubricants without excessive wear or damage.

Erosion – The wearing away of a surface by an impinging fluid or solid

Ester – An organic compound formed by the reaction of an acid (organic or inorganic) with an alcohol.

Ethanol – Ethyl alcohol mainly formed through fermentation. (alcoholic drinks, component in gasohol)

Ethylene Glycol – A colorless, syrupy liquid, used as an antifreeze in cooling and heating systems.

Evaporation Loss – The loss of a portion of a lubricant due to volatization.

Fillers – A term normally used to denote something non-chemical added to an oil or grease, i.e., moly, graphite, zinc oxide.

Film Strength – The ability of a lubricant film to withstand the effects of speed, temperature and load without breaking down.

Filter – Any device or porous substance used for cleaning and removing suspended matter from a gas or fluid.

Fire Point – The temperature where a lubricant, when subjected to a source of ignition or flame, ignites & continues to burn.

Fire Resistant Fluid – A fluid, difficult to ignite, that shows little tendency to propagate flame.

Flash Point (C.O.C.) – The temperature to which a combustible liquid must be heated to give off substantial vapor to form a momentarily flammable mixture with air when a small flame is applied under specific conditions.

Fluid – Liquid, gas or combination thereof.

Fluid Friction – Occurs between the molecules of a gas or liquid in motion, and is expressed as shear stress. Unlike solid friction, fluid friction varies with speed and area.

Fluid Power – Energy transmitted and controlled through use of a pressurized fluid within an enclosed circuit.

Foam – An agglomeration of gas bubbles separated from each other by a thin liquid film. If an oil is said to not foam, the small air bubbles will quickly combine, become larger bubbles, and then break to vent to the atmosphere. If this action occurs slowly, the oil is said to foam.

Four Ball Test – Machine used to evaluate a lubricants antiwear qualities, frictional characteristics, or load carrying capabilities. There are four steel -inch balls. Three of the balls are clamped together in a cup filled with lubricant while the fourth ball is rotated against them. Two test procedures are based on this same principle the Four Ball EP Test (ASTM D-2596) and Four Ball Wear Test (ASTM D-2266).

Four Stroke Engine – An internal combustion engine that requires two revolutions of the crankshaft to complete all four cycles.

Fretting – Wear resulting from small amplitude motion between two surfaces; may produce red or black oxide.

Friction – Resistance to motion of one object over another. Friction depends on the smoothness of the contacting surfaces, as well as the force with which they are pressed together.

Fuel Dilution – The amount of unburned fuel present in the lubricant. This test will indicate problems such as fuel line, injector, carburetor and pump leaks. Fuel dilution is accurate down to less than 0.5%.

Full Film Lubrication – Complete separation of mated surfaces. No metal-to-metal contact.

Full-Flow Filtration – A system of filtration in which the total flow of a circulating fluid system passes through a filter prior to component delivery.

Gears – Toothed machine parts for transmitting power from one shaft to another.

Gravity – The mass/volume relationship of lubricants used in determining volume requirements for specific mass of products (packaging).

Grease – Lubricant composed of an oil or oils thickened with a soap, soaps or other thickener to a semi-solid consistency.

Gum – A rubber like, sticky deposit black or dark brown in color resulting from the oxidation of lubricating oils from unstable constituents in gasoline, which deposit during storage or use.

High Temperature High Shear Rate Viscosity (HTHS) – A measure of a fluids resistance to flow under conditions resembling highly-loaded journal bearings in fired internal combustion engines, typically 1 million s-1 at 150oC.

Horsepower – A measurement of an engines power, equal to 550 foot pounds of torque per second.

Hydrocarbons – Compounds of hydrogen & carbon of which petroleum products are typical examples. Also known as organic compounds.

Hydrodynamic Lubrication – The formation of a continuous lubricating fluid film between mating surfaces of sufficient pressure to prevent contact

Hydro finishing – A process for treating raw extracted base stocks with hydrogen to saturate them for improved stability.

Hydrolytic Stability – Ability of additives and certain synthetic lubricants to resist chemical decomposition (hydrolysis) in the presence of water.

Hypoid Gear Lubricant – A gear lubricant having extreme pressure characteristics for use in hypoid type gears (as in the differential of an automobile).

Incompatibility – When a mixture of two or more substances shows physical properties or service performance characteristics, which are inherently inferior to those of either of the individual products before mixing.

Inhibitor – Additive that improves the performance of a petroleum product by controlling undesirable chemical reactions, i.e., oxidation inhibitor, rust inhibitor, etc.

Insolubles – Contaminates found in used oils due to dust, dirt, wear particles or oxidation products.

Journal – Part of shaft or axle that rotates or angularly oscillates in or against a bearing or about which a bearing rotates or angularly oscillates.

Keg – Container which would typically hold 16 gallons of oil or approximately 120 pounds of a grease-type product. Also called a quarter drum.

Kinematic Viscosity – Measure of a fluids resistance to flow under gravity at a specific temperature (usually 40C or 100C).

Lubrication – Control of friction and wear by the introduction of a friction reducing film between moving surfaces in contact. May be a fluid, solid or plastic substance.

Material Safety Data Sheet (MSDS) – Vital information regarding the safe handling and storage of a product.

Micron – A millionth of a meter, or 0.0000394 inch.

Mineral Oil – Term applied to a wide range of products that is typically used when referring to petroleum-based lubricants.

Mini Rotary Viscometer – An instrument used to measure the borderline pumping temperature (BPT) of engine oils from 0C to -40C. BPT is the lowest temperature at which engine oil can be supplied in adequate amounts to the oil pump inlet.

Multi-viscosity/Multi Grade Oil – Engine or gear oil that meets the requirements of more than one SAE viscosity grade classification, and that can be used over a wider temperature range than a single grade oil.

Naphthenic – A type of petroleum fluid derived from naphthenic crude oil, containing a high proportion of closed-ring methylene groups.

Neutralization Number – A measure of the acidity or alkalinity of an oil.

Newtonian Flow – Occurs in a liquid system where the rate of shear is directly proportional to the shearing force, as with straight grade oils which do not contain polymeric viscosity modifier. When rate of shear is not directly proportional to the shearing force, flow is non-Newtonian, as it is with oils containing viscosity modifiers.

Nitration – Process where nitrogen oxides attack petroleum fluids at high temperatures, often resulting in viscosity increase and deposit formation. Nitration only occurs in applications where fuel is used.

NLGI – National Lubricating Grease Institute, an industry group that monitors grease and sets penetration standards for grading greases.

NLGI Number – A scale for comparing the consistency (hardness) range of greases.

Octane Number – A measure of a fuels ability to prevent detonation in a spark-ignition engine.

Organic Acid – An organic compound, with acid properties, obtained from organic substances such as animal, vegetable and mineral oils, i.e., a fatty acid.

Oxidation – Occurs when oxygen attacks fluids. The process is accelerated by heat, light, metal catalysts and the presence of water, acids, or solid contaminants. It leads to increased viscosity and deposit formation.

Oxidation Inhibitor – Substance added in small quantities to an oil product to increase its oxidation resistance, thereby lengthening its service or storage life. Also called an antioxidant.

Oxidation Stability – Resistance of an oil product to oxidation and, therefore, a measure of its potential service or storage life.

Oxygenated Fuels – Fuels for internal combustion engines that contain oxygen combined in the molecule, e.g., alcohols, ethers and esters. Term also applies to blends of gasoline with oxygenates, e.g., Gasohol, which contains 10% by volume of anhydrous ethanol in unleaded gasoline.

Paraffin – Hydrocarbons belonging to the series starting with methane (CH4). Paraffins are saturated with respect to hydrogen. High molecular weight paraffins are solid such as paraffin wax.

Particle – A minute piece of matter with observable length, width and thickness, usually measured in micrometers.

PCV (Positive Crankcase Ventilation) Valve – An emissions control device that allows gases from the crankcase to be reintroduced into the intake.

Penetration – A test in which a cone is dropped into a grease sample to measure the penetration or how hard or soft the grease is at room temperatures. The cone penetrates farther in a soft grease and therefore has a higher penetration number. This penetration relates to an NLGI number. A number 0 grease is called an NLGI 0 grade and will be softer than an NLGI 1 or 2 grade.

pH – A measure of acidity or alkalinity. Values of pH run from 0-14; 7 indicating neutrality, numbers less than 7 indicate increasing acidity, and numbers greater than 7 indicate increasing alkalinity.

Pitting – Surface cavities, may be related to fatigue, overload or corrosion.

Pneumatics – Engineering science pertaining to gaseous pressure and flow.

Poise – Unit of viscosity, defined by the shear stress required to move one layer of fluid along another over a total thickness of one centimeter at a velocity of one centimeter per second. This viscosity is independent of fluid density, and directly related to flow resistance.

Polishing (bore) – Excessive smoothing of the surface finish of the cylinder bore or cylinder liner in an engine to a mirror-like appearance, resulting in depreciation of ring sealing and oil consumption performance.

Polymerization – Chemical combination of similar type molecules to form larger molecules.

Pour Point – An indicator of the ability of an oil or distillate fuel to flow at cool operating temperatures. It is the lowest temperature at which the fluid will flow when cooled under prescribed conditions.

Pour Point Depressant – Additive used to lower the pour point or lower the temperature fluidity of a petroleum product.

Preignition – Ignition of the fuel/air mixture in a gasoline engine before the spark plug fires. Often caused by incandescent fuel or lubricant deposits in the combustion chamber, it wastes power and may damage the engine.

Propylene Glycol – A non-toxic liquid used as a coolant/antifreeze in cooling and heating systems.

Pumpability – The low temperature, low shear stress-shear rate viscosity characteristics of an oil that permit satisfactory flow to and from the engine oil pump and subsequent lubrication of moving components.

Refining – Series of processes to convert crude oil and its fractions into finished petroleum products, which may include thermal cracking, catalytic cracking, polymerization, alkylation, reforming, hydrocracking, hydrofoaming, hydrogenation, hydrogen treating, Hydrofining, solvent extraction, dewaxing, de-oiling, acid treating, clay filtration, deasphalting, etc.

Re-refining – A process of reclaiming used lubricant oils and restoring them to a condition similar to that of virgin stocks by filtration, clay adsorption or more elaborate methods.

Ring Sticking – Freezing of a piston ring in its groove in a piston engine or reciprocating compressor due to heavy deposits in the piston ring zone.

Rust – Slow oxidation of iron.

Rust Preventative – Compound for coating iron surfaces with a film that protects against rust. Commonly used to preserve equipment in storage.

SAE Grade – Numbers applied to automotive lubricants to indicate their viscosity range.

Saybolt, Saybolt Universal Seconds, SUS, or SSU – The most common viscosity measurement prior to the international acceptance of centistokes, SUS measurements are now obsolete. To convert measurements from SUS at 100F to an approximate value in cSt at 40C (ISO viscosity grade), divide the SUS value by 5.

Scoring – Scratches on mechanical parts in the direction of motion caused by abrasive contaminants.

Scuffing – Abnormal engine wear due to localized welding and fracture. It can be prevented through the use of antiwear, extreme-pressure and friction modifier additives. See adhesion.

Semi Fluid – Any substance having attributes of both a liquid and a solid. Similar to semi solid but being more closely related to a liquid than a solid.

Shearing – Relative slipping or sliding between one part of a substance and an adjacent part.

Shear Stability – Ability of a lubricant to withstand shearing forces without being degraded to lower viscosity or consistency.

Sludge – A thick, dark residue, normally of mayonnaise consistency, that accumulates on nonmoving engine interior surfaces. Generally removable by wiping unless baked into a carbonaceous consistency, its formation is associated with insolubles overloading the lubricant.

Solid – Any substance having definite shape that it does not readily relinquish. More generally, any substance in which the force required to produce a deformation depends upon the magnitude of the deformation rather than the rate of deformation.

Stoichiometric – Ratio of fuel to air where the exact proportions for complete reaction of both, with none left over, are present.

Stoke (St) – Kinematic measurement of a fluids resistance to flow defined by the ratio of the fluids dynamic viscosity to density.

Supercharger – A device for increasing the pressure and hence the mass of air and fuel burned on each firing stroke. Driven by the crankshaft; therefore, displacement is fixed and directly related to engine RPMs.

Surface Tension – The contractile surface force of a liquid by which it tends to assume a spherical form and to present the least possible surface. It is expressed in dyne/cm or ergs/cm.

Synthetic Lubricant – Fluid made by chemically reacting materials to produce a lube with a specific chemical composition, which has planned, and predictable properties.

Thermally Stable – Ability to withstand temperatures without decomposing. Not to be confused with oxidation stability where oxygen must be present and oxidation rather than decomposition.

Thickener – The metallic soap or other material used to combine with oil or other lubricating fluid to make a grease.

Torque – The twisting force with which the engines crankshaft actually rotates, measured in foot-pounds.

Total Acid Number (TAN) – The quantity of base, expressed in milligrams, that is required to neutralize all acidic constituents present in one gram of sample.

Total Base Number (TBN) – The quantity of acid, expressed in terms of the number of milligrams that is required to neutralize all basic constituents present in one-gram sample.

Total Solids – The total amount of solids contamination, both suspended and non-suspended present in the lubricant. This test is indicative of carburetion problems (too rich or too lean), if the oil filter has reached the saturation point and is no longer able to remove contamination from the system, and if the air intake system is functioning properly and allowing enough air into the unit for complete burn to take place.

Tribology – Science of the interactions between surfaces moving relative to each other, including the study of lubrication, friction and wear.

Turbine – A device consisting of blades attached to a disc or rotor, which converts flow into rotary action.

Turbocharger – A device for increasing the pressure and hence the mass of air and fuel burned on each firing stroke. A turbine of exhaust gases drives a compressor; therefore, efficiency is variable and related to exhaust pressure.

Vapor Lock – Condition wherein the fuel boils in the fuel system forming bubbles that retard or stop the flow of fuel to the engine.

Varnish – A thin, insoluble, non-wipeable film occurring on interior engine parts.

Viscosity – Measure of a fluids resistance to flow.

Viscosity Index (V.I.) – Relationship of viscosity to temperature of a fluid. High viscosity index fluids tend to display less change in viscosity with temperature than low viscosity index fluids.

Viscosity Index Improver (V.I.I.) – Additive to improve or increase the viscosity index. A VI improver increases an oils resistance to thinning as it is heated. It is commonly used in multi-viscosity or multigrade oils. Since a VI improver increases the viscosity as well as the viscosity index, it must be taken into consideration when formulating oil. (Example: taking an oil in the SAE 30 range, adding a VI improver could give an oil like a SAE 40)

Viscosity Modifier – See V.I.I. Additive, usually a high molecular weight polymer that reduces the tendency of an oils viscosity to change with temperature.

Wear – Damage resulting from the removal of materials from surfaces in relative motion.

Zinc (ZDP) – Commonly used name for zinc dithiophosphate, an antiwear/oxidation inhibitor chemical