This test method is a measure of the resistance of the coal to breakage upon impact and abrasion as the coal rubs together and against the walls of the transportation vehicle.

1.1 This test method covers the determination of the relative friability of a particular size of sized coal. It affords a means of measuring the liability of coal to break into smaller pieces when subjected to repeated handling at the mine or subsequently, by the distributor or by the consumer. This test method is serviceable for ascertaining the similarity of coals in respect to friability rather than for determining values within narrow limits to emphasize their dissimilarity. This test method also may serve to indicate the relative extent to which sized coals will suffer size degradation in certain mechanical feed devices. This test method may be used for differentiating between certain ranks and grades of coal, and therefore the test method is of service for coal classification purposes.

1.2 The values stated in inch-pound units shall be regarded as the standard. Mass may be expressed in metric values.

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.