Glossary

Additive that reduces metal-to-metal wear under boundary lubrication by forming a protective tribofilm on surfaces.

Antioxidants slow lubricant oxidation, helping control viscosity increase, acid formation, sludge, and varnish during service.

API service classifications identify engine-oil performance categories and help match lubricants to gasoline or diesel engine requirements.

Base Oil Groups classify lubricant base stocks by composition and performance-related characteristics, creating a common language for formulation...

Additive that protects non-ferrous metals (copper, brass, aluminum) from chemical attack by forming passive surface films.

Metallic additive (sulfonate, phenate, or salicylate) that neutralizes acids and keeps engine components clean.

Dispersants help keep soot, sludge precursors, and oxidation by-products suspended in the lubricant so they are less likely...

Surfactant additive that stabilizes oil-water emulsions in metalworking fluids and industrial applications by reducing interfacial tension.

Additive that reacts with metal surfaces under extreme load and temperature to prevent welding, scoring, and scuffing.

Lowest temperature at which lubricant vapor ignites with an ignition source; used for safety classification and transportation regulations.

Additive (typically silicone-based) that prevents or collapses foam in lubricating oils and hydraulic fluids to maintain film integrity.

Additive that reduces friction coefficient in boundary and mixed lubrication to improve fuel efficiency and meet OEM friction...

HTHS viscosity measures lubricant resistance to flow under high temperature and high shear, making it a key indicator...

Japanese lubricant standards for motorcycle (MA, MA2, MB) and 2-stroke (FC, FD) engine oils.

A fluid ability to reduce friction and wear between sliding surfaces, especially relevant for diesel fuel, metalworking fluids,...

Additive (benzotriazole, tolyltriazole) that prevents copper and other metals from catalyzing oil oxidation, used at very low concentrations.

Evaporative loss measurement (% mass at 250C for 1 hour); indicates oil consumption tendency and compliance with API/ACEA...

A lubricant resistance to oxygen-induced degradation that produces acids, sludge, and varnish during service.

Pour point is the lowest temperature at which an oil will flow under gravity. It indicates cold-weather pumpability...

Additive that prevents iron oxide formation on ferrous surfaces by displacing water and forming a protective adsorption film.

Resistance of viscosity modifier polymers to permanent viscosity loss under mechanical shear in engine and gear oil service.

TBN measures an oil's reserve alkalinity and indicates how much acid-neutralizing capacity remains in the formulation during service.

Viscosity Index, or VI, expresses how strongly a lubricant's viscosity changes with temperature. Higher VI means more stable...

Polymer additive that reduces the rate of viscosity change with temperature, enabling multigrade oil formulations (e.g., 5W-30).

ZDDP is a multifunctional antiwear additive widely used in lubricants to form protective tribofilms under load while also...