ASTM D6821-25
Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer
| Standard number: | ASTM D6821-25 |
| Released: | 01.11.2025 |
| Status: | Active |
| Pages: | 7 |
| Section: | 05.03 |
| Keywords: | apparent viscosity; low-temperature flow properties; low-temperature viscosity; mini-rotary viscometer; viscosity; yield stress; |
| ASTM number: | ASTM D6821 |
| Supersedes: | D6821-20A |
1.1 This test method covers the measurement of the viscosity of drive line lubricants (gear oils, automatic transmission fluids, and so forth) with a constant shear stress viscometer at temperatures from –40 °C to 10 °C after a prescribed preheat and controlled cooling to the final test temperature. The precision is stated for test temperatures from –40 °C to –26 °C.
1.2 The applicability of this particular test method to petroleum products other than drive line lubricants has not been determined.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3.1 This standard uses the SI based unit of milliPascal second (mPa·s) for viscosity which is equivalent to centiPoise (cP).
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
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.