Two lubricating greases are incompatible when a mixture of the products has physical or performance properties that are inferior to those of the individual greases. Physical or performance properties inferior to one of the products and superior to the other may be due to simple mixing and would not be considered as evidence of incompatibility.

A period of time during which oxidation occurs at a relatively slow rate. At the end of the induction period, the oxidation rate may become more rapid. Methods of measurement of induction time include ASTM D942 and D5483.

An acid that does not contain a carbon chain. Inorganic acids, such as boric acid, are sometimes used as complexing agents in complex soap greases. Contrast with Organic Acid.

The reaction product of an alkali with an inorganic acid. Inorganic salts, such as lithium borate, are sometimes found in complex soap greases.

See Non-Soap Thickener.

Components of a lubricating grease that are insoluble in the prescribed solvents in an analytical procedure such as ASTM D128. The analytical procedure should be indicated when specifying insolubles. Additional identifying analytical tests are required to determine the nature and composition of insolubles, which may consist of fillers, additives, certain types of thickeners, or impurities.

The International Organization for Standardization, a non-governmental, independent organization with a membership of 166 national standards bodies, is based in Geneva, Switzerland. It has developed and published more than 24,000 international standards covering almost all aspects of technology and manufacturing.