ASTM D2422-97(2018)

1.1 This classification is applicable to all petroleum-base fluid lubricants and to those nonpetroleum materials which may be readily blended to produce fluid lubricants of a desired viscosity, that is, lubricants for bearings, gears, compressor cylinders, hydraulic fluids, etc.

1.2 This classification is applicable to fluids ranging in kinematic viscosity from 2 cSt to 3200 cSt (mm²/s) as measured at a reference temperature of 40 °C. In the category of petroleum-base fluids, this covers the range from kerosene to heavy cylinder oils.

1.3 Fluids of either lesser or greater viscosity than the range described in 1.2 are, at present, seldom used as industrial lubricants. Should industrial practices change, then this system, based on a mathematical series of numbers, may be extended to retain its orderly progression.

1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.