ASTM D1478 test method for low-temperature torque of ball bearing grease
1. Scope
1.1 This test method covers the determination of the extent to which a grease retards the rotation of a slow-speed ball bearing by measuring starting and running torques at low temperatures (below -20°C (0°F)).
1.1.1 Torque measurements are limited by the capacity of the torque-measuring equipment.
NOTE 1 - When initially developed, the original dynamometer scale limited the torque capacity to approximately 30 000 g•cm; the original dynamometer scale is obsolete, however. The suggested replacement scale has not been evaluated; it could extend the limit to approximately 75 000 g•cm.
1.2 The values stated in SI units are to be regarded as the standard in this test method, except for torque values which are given in cgs-metric units, which are universally used in grease specifications. Other units are provided for information only.
1.3 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 and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard and warning statements, see Note 2, Note 4, Note 5, Note 6, and Note 8.
2. Referenced Documents
2.1 ASTM Standards:
D235 Specification for Mineral Spirits (Petroleum Spirits) (Hydrocarbon Drycleaning Solvents)
D4693 Test Method for Low-Temperature Torque of Grease-Lubricated Wheel Bearings Test Methods for Rating Motor, Diesel, and Aviation Fuels; Motor Fuels (Section I), Reference Materials and Blending Accessories (Annex 2), Reference Materials (A2.7), and Table 32; (Specification for ASTM Knock Test Reference Fuel, n-heptane)
2.2 ANSI/AFBMA Standard:
Standard 20-1987 Radial Bearings of Ball, Cylindrical, Roller, and Spherical-Roller Type - Metric Designs (AFBMA Code 20BCO2JO)
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 low-temperature torque, n - the torque in g•cm required to restrain the outer ring of a No. 6204 size open ball bearing lubricated with the test grease while the inner ring is rotated at 1 +/- 0.05 r/min at the test temperature.
3.1.2 running torque, n - the 15-s average value of the torque after rotation for a specified period of time (60 min).
3.1.3 starting torque, n - the maximum torque measured at the start of rotation.
