These cone penetration tests not only evaluate the consistency of lubricating greases over the full range of NLGI numbers from 000 to 6, but also evaluate the consistency of stiff greases having penetration numbers less than 85. In contrast, Test Method D 937 is aimed at petrolatums and Test Method D 1403 uses less precise one-quarter and one-half scale equipment intended for use when the sample quantity is limited.

Cone penetration test results provide one measure of the consistency of a grease. Worked penetration results are required to determine to which NLGI consistency grade a grease belongs. Undisturbed penetration results provide a means of evaluating the effect of storage conditions on grease consistency.

Although no correlation has been developed between cone penetration results and field service, the cone penetrations obtained by the four procedures are widely used for specification purposes, such as in users' material specifications and suppliers' manufacturing specifications.

1.1 These test methods cover four procedures for measuring the consistency of lubricating greases by the penetration of a cone of specified dimensions, mass, and finish. The penetration is measured in tenths of a millimetre.

1.1.1 The procedures for unworked, worked, and prolonged worked penetration are applicable to greases having penetrations between 85 and 475, that is, to greases with consistency numbers between NLGI 6 and NLGI 000. An undisturbed penetration test, described in Appendix X1, is similar to the unworked penetration test.

1.1.2 The block penetration procedure is applicable to greases that are sufficiently hard to hold their shape. Such greases usually have penetrations below eighty-five tenths of a millimetre.

1.2 None of the four procedures is considered suitable for the measurement of the consistency of petrolatums by penetration. Test Method D 937 should be used for such products.

1.3 The dimensions of the equipment described in these test methods are given in inches and fractions of an inch. These units were retained because a vast body of data has been obtained using equipment with the dimensions shown. Metric equivalency tables are provided with each figure. Temperatures and other dimensions are given in the preferred SI units; the values shown in parentheses are provided for information.

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 and health practices and determine the applicability of regulatory limitations prior to use.