1.1 This specification covers high hardenability modifications of high-carbon bearing quality steel to be used in the manufacture of antifriction bearings. 1.2 Supplementary requirements of an optional nature are provi This specification covers high hardenability modifications of high-carbon bearing quality steel to be used in the manufacture of antifriction bearings. The grades of steels covered here are: Grade 1, Grade 2, Grade 3, Grade 4, Grade B2, Grade B3, Grade