Certified Lubrication Specialist Practice Test

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• Which term describes the appearance and feel of grease?
• Recommended for extreme temperature applications and extended service life.
• Synthetic compressor lubricants with clean discharge valves.
• The acronym STLE stands for which organization?
• Which statement best describes how temperature affects lubricant film thickness?
• Name practices to minimize contaminants entering lubricant during maintenance.
• What is the function of antioxidants in lubricants?
• Which oil type is refined to meet food-grade and pharmaceutical safety standards?
• Microscopic peaks and valleys on an apparently smooth surface are called?
• What term describes lubrication between rubbing surfaces without a full fluid film?
• Include layer-lattice solids like graphite and molybdenum disulfide.
• Which category is described as Solid Organic Compounds?
• Why are anti-foam additives included in some lubricants?
• Which property describes the lubricant's load-carrying capacity in a lubricating film?
• ISO VG rating indicates viscosity at what temperature?
• Elastohydrodynamic lubrication is characterized by elastic deformation of surfaces and a very thin film under high load.
• Which oil type is generally recommended for most industrial lubricants, except in cold temperatures?
• Distinguish progressive and circulating centralized lubrication systems.
• Which term denotes a grease-like product formed when a thickener is dispersed in an oil?
• Centipoise unit used for reporting viscosity.
• Which property describes the grease's ability to resist deterioration due to chemical reactions?
• What is a key benefit of maintaining an adequate oil film in bearings and pumps?
• Which practice ensures LO sampling is representative?
• Which property describes the lubricant's ability to maintain a lubricating film under load?
• Which parameter is used to describe how viscosity of a lubricant changes with temperature?
• Anti-wear additives primarily reduce wear by
• Which option would be described as generally suitable for most industrial lubricants but not in very cold conditions?
• Tribology is the study of which topic?
• Which factor is not typically considered when determining relubrication intervals?
• What term is a dimensionless parameter used to assess turbulent flow in pipes?
• What is the lowest temperature at which oil will ignite vapors with a flame?
• Which oil type is characterized by wax-free behavior due to its molecular structure?
• In boundary lubrication, what is a typical anti-wear additive used in boundary films?
• Which term describes a material that is an insulator and can be polarized by an electric field?
• Which statement best compares ester-based lubricants to mineral-based lubricants?
• Which lubrication regime relies on additive films as the primary load-bearing mechanism?
• Why is cleanliness critical for lubrication storage and handling?
• Which lubrication regime involves a full lubricating film between surfaces?
• Which term describes an oil's tendency to separate from water?
• Which term is used to describe the viscosity grade standard for lubricants?
• VI stands for which concept?
• What are common consequences of poor lubrication in rolling element bearings?
• How should oil drain intervals be determined in a lubrication program?
• Define kinematic viscosity and viscosity index and explain why both are important for equipment lubrication?
• Which term refers to the study of surface interactions, friction, wear, and lubrication?
• Which term describes roughness measured along the centerline of a surface?
• What does oxidation stability indicate in lubricants and how is it assessed?
• Which term describes a mixture of oil and water or oil additives?
• What common test is used to quantify water content in oil?
• Which property describes grease's ability to recover to original grade after shear?
• Pour Point is defined as what?
• What does the NLGI grease grade indicate and how does it relate to application?
• Which property describes resistance to oil degradation over time?
• What does NLGI stand for?
• What term describes the temperature at which grease transitions from solid to liquid?
• Specific gravity is defined as?
• Circulating systems require oil that does what?
• Which property is directly related to the flash point?
• Polytetrafluoroethylene is commonly known by what name?
• The viscosity quantity expressed in centistokes is called?
• Which term describes a mixture of oil and water or oil additives?
• Which property is described as the evaporation rate?
• Which statement correctly describes the three main tribological lubrication regimes and a key characteristic of each?
• Which oils are inert and expensive for high temperatures and specialty applications?
• Which term describes the density relative to water at the same temperature?
• Which base stock group is produced by hydrocracking and widely used as a highly refined mineral oil?
• Which term describes petroleum fluid density measured as API gravity?
• How does improper lubrication contribute to gear pitting?
• What does a rising copper (Cu) level in oil suggest?
• What is the role of metering blocks or valves in a centralized lubrication system?
• Which action best helps prevent leaks and maintain lubrication cleanliness?
• List three base oil families used in industrial lubricants and one typical use for each.
• Which material is used as an example of polymer films for low friction?
• Which hydrocarbon class consists of hydrogen and carbon molecules with at least one ring?
• Which term is a measure of an oil's resistance to viscosity change with temperature?
• What is the approximate density of water at standard conditions?
• Which parameter is defined by the formula ZN/P, where Z is viscosity, N is speed, and P is load?
• Rheopectic describes grease that thickens with what?
• Turbulent flow is defined as flow where molecules do what?
• Which lubricant is recommended for high temperatures and oxygenated environments?
• Which property refers to preventing corrosion in idle machinery?
• Highly refined oils produced by hydrocracking are known as which base stock group?
• What is the meaning of shear in materials science?
• Which factors influence grease life at a lubrication point?
• Rapeseed or canola oils are used as a base for biodegradable hydraulic fluids.
• Which grease consistency and lubrication approach are typical for rolling-element bearings in machines?
• Emulsified water in oil can lead to which issue?
• Which property measures the ability of oil to separate from water?
• In moisture-prone environments, how does water resistance of grease influence suitability?
• Which term describes a substance that behaves as a complete fluid?
• Which term describes a grease property that thickens with shear?
• Which ester-based lubricant is specifically used for fire resistance in aviation hydraulics?
• Which storage practice helps reduce abrasive contamination in stored lubricants?
• What term refers to the control of friction and wear by introducing a film between surfaces?
• In a progressive centralized lubrication system, what is the role of metering valves?
• What are TAN and BN and why are they important in used oil analysis?
• What is the primary role of filtration in a lubrication system?
• Which lubrication concept uses a combination of viscous fluid and additives?
• Which statement about biodegradability of ester-based lubricants is most accurate?
• Temperature when wax crystals appear in lubricating oil is known as the
• Highly refined oils meeting food and drug requirements are called what?
• Which term describes Elasto-Hydrodynamic Lubrication under high loads?
• Which statement best describes a basic plan for collecting an oil sample for LO analysis?
• Which term refers to how viscosity of the base oil affects grease performance?
• Soluble for additives, good for low temperature applications.
• What defines a progressive centralized lubrication system?
• ISO VG stands for?
• Which ester category is used for compressor lubricants with clean discharge valves?
• Which term means the resistance to motion between objects?
• Which property measures the ratio of a lubricant's density to the density of water?
• Which property is the temperature at which a lubricant will ignite and sustain combustion for 5 seconds?
• What is the standard NLGI grease grade commonly used for bearing applications?
• Wear debris analysis checks metal particles in oil to gauge wear; which metals are commonly monitored?
• Which concept describes a grease's ability to prevent oil from separating within the grease matrix?
• Which term describes having particles that easily move and yield to pressure, capable of flowing?
• Which item is a typical component of a centralized lubrication system?
• Thin films between surfaces to reduce friction and wear.
• Oil's ability to separate from water is called which term?
• The rate of oxidation of petroleum oils doubles every ________ degrees.
• Left behind by paraffinic oils when oxidized, hard and sticky?
• If antioxidants are depleted, what condition develops?
• Which term describes loss of surface material due to motion between surfaces?
• What is ZDDP and a typical concern in some applications?
• Particles moving in a straight, parallel flow path describes which flow category?
• Centipoise is the unit for reporting which viscosity?
• Wax appearance point refers to which condition?
• How does temperature affect lubricant viscosity and film formation?
• Which term describes the rate at which a liquid evaporates?
• Volatility describes a fluid's tendency to do what?
• What is lube life in lubrication management?
• What does water washout resistance describe in grease performance?
• Which property indicates how easily grease can be pumped through long piping lines?
• What is the purpose of a contamination control program in lubrication management?
• Which term is defined as a fluid's resistance to flow?
• Which term describes a grease's resistance to oxidation?
• Compare soap-based grease thickeners with non-soap thickeners and give an example of each.
• How does water contamination affect lubricant performance?
• What does EHL stand for?
• What term refers to hydrogen and carbon molecules with at least one double bond?
• Which additive is associated with ash formation and catalyst poisoning in engines?
• Which statement best describes the purpose of an oil-water separator in a lubrication system?
• Which factors determine the relubrication interval for grease-lubricated bearings?
• What is pour point and why is it important in cold climates?
• Which lubrication regime is characterized by a full fluid film separating surfaces and is typically associated with moderate to high speeds?
• Which term refers to the wax derived from petroleum with high molecular weight?
• Which property indicates how viscosity changes with temperature?
• Used where fire resistance is crucial, like aviation hydraulics.
• What term denotes the hard, sticky residue formed after oxidation of paraffinic oils?
• Define boundary lubrication and name a typical additive used in boundary films.
• Semi-solid dispersion of thickening agent in a liquid base oil.
• Thixotropy describes which behavior?
• Which property is concerned with preventing oil separation from grease?
• Rising nickel or chromium in LOA data indicates wear of which components?
• Viscosity is the fluid's resistance to flow.
• Which lubricant is used neat or mixed with water and provides excellent lubricity for gear applications?
• Provide a practical method for improving lubricant cleanliness in a plant.
• Which term denotes inorganic coatings formed on metal surfaces through a chemical reaction?
• Thermal conductivity describes which property?
• Used in low temperatures, leaving soft and fluffy deposits.
• What temperature is the viscosity of industrial oils generally reported at?
• Which category includes graphite and molybdenum disulfide as layered solids used for lubrication?
• Which diagnostic signs indicate scuffing or pitting due to an inadequate lubricant film?
• Name two common lubrication system configurations used in industrial plants.
• Moisture contamination can lead to which lubrication-related failure mode?
• Which property describes a fluid's tendency to evaporate?
• What term describes carbon and hydrogen molecules without double bonds?
• Which standard is commonly used to classify particulate contamination in hydraulic fluids?
• Force to move a body over a surface divided by body weight is described by which coefficient?
• Which concept refers to maintaining grease consistency under stress?
• Which term describes hydrocarbons with at least one double bond?
• Which statement about wear debris analysis is true?
• Used for fire-resistant hydraulic fluids and jet engine lubricants.
• Which fluid offers better oxidation resistance and higher temperature stability?
• Inorganic compounds developed on metal surfaces by chemical reactions.
• How do anti-wear additives function in boundary lubrication?
• Which term describes a lubricant class that reduces wear by forming a protective film at the contact interface?
• Bearing corrosion due to moisture contamination will show which diagnostic signs?
• What does ISO VG 32 indicate?
• Which concept refers to the impact of base oil viscosity on grease performance?
• Less volatile than petroleum oils, suitable for engine applications.
• Which products have controlled dielectric properties?
• Saybolt Seconds Universal (SSU) is a measure of which property?
• What is a beta ratio in filtration and what does a higher value indicate?
• Which methods are used to assess oxidation stability in lubricants?
• Name two common lubricant additive categories and their primary function.
• Which property indicates a lubricant's resistance to oil degradation over time?
• Which term describes the grease's ability to resist water exposure?
• Define cavitation in lubrication systems and how proper lubrication helps prevent it.
• Average height of peaks and valleys on a surface is called which term?
• What property is defined as the ratio of a lubricant's density to the density of water?
• What is the ratio of a substance's density to the density of water called?
• Which category includes plant-based oils used for biodegradable hydraulic fluids?
• Which of the following pairs correctly matches a lubrication-related failure mode with a diagnostic sign?
• Which term describes lubrication that provides a full film to separate surfaces under load?
• Type of thickener made through saponification of fatty material.
• Paraffin Wax is best described as what?
• Which term refers to hydrogen and carbon molecules with at least one ring?
• Which statement best describes TAN/BN ratio usage?
• Name two oil analysis tests and what they help determine.
• Which property describes a substance's ability to degrade to carbon dioxide and water in the presence of water, nutrients or microorganisms?
• Rheology studies what?
• Centistoke is the unit for reporting which viscosity measure?
• Reynolds Number measures what?
• Which property measures the depth to which a grease can penetrate under specified test conditions?
• What is the effect of entrained air on oil film formation?
• Molecules with excellent lubricity, stability, and no wax formation.
• Which term refers to microscopic roughness on a seemingly smooth surface?
• Polytetrafluoroethylene (Teflon) is commonly used as what type of material?