ASTM D6821-14
Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer

Standard No.

ASTM D6821-14

Release Date

2014

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM D6821-17

Latest

ASTM D6821-20a

Scope

5.1 Viscosity of drive line lubricants at low temperature is critical for both gear lubrication and the circulation of the fluid in automatic transmissions. For gear oils (GOs), the issue is whether the fluid characteristics are such that the oil will flow into the channel dug out by the submerged gears as they begin rotating and re-lubricating them as they continue to rotate. For automatic transmission fluids, torque, and tractor fluids the issue is whether the fluid will flow into a pump and through the distribution system rapidly enough for the device to function.

5.2 The low temperature performance of drive line lubricant flow characteristics was originally evaluated by the channel test. In this test, a pan was filled to a specified depth of approximately 2.5 cm and then cooled to test temperature. The test was performed by scraping a channel through the full depth of the fluid and across the length of the pan after it had soaked at test temperature for a specified time. The time it took the fluid to cover the channel was measured and reported. The channel test was replaced by Test Method D2983 in 1971.

5.3 The results of this test procedure correlate with the viscometric measurements obtained in Test Method D2983.4 The correlation obtained is:

where:
V	=	the apparent viscosity measured by this test method, and
VD2983	=	the apparent viscosity measured by Test Method D2983.

5.3.1 The equation was obtained by forcing the fit through zero. The coefficient of variation (R²) for this correlation is 0.9948.

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 –408201;°C to 108201;°C after a prescribed preheat and controlled cooling to the final test temperature. The precision is stated for test temperatures from –408201;°C to –268201;°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......

ASTM D6821-14 history

• 2020 ASTM D6821-20a Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer
• 2020 ASTM D6821-20 Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer
• 2018 ASTM D6821-18 Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer
• 2017 ASTM D6821-17 Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer
• 2014 ASTM D6821-14 Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer
• 2012 ASTM D6821-12 Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer
• 2007 ASTM D6821-02(2007) Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer
• 2002 ASTM D6821-02e1 Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer
• 2002 ASTM D6821-02 Standard Test Method for Low Temperature Viscosity of Drive Line Lubricants in a Constant Shear Stress Viscometer