ASTM A 646 : 1995 : R1999

1.1 This specification covers premium quality alloy steel semifinished rolled or forged blooms and billets for reforging into critical parts such as aircraft landing-gear forgings.

1.2 Blooms and billets, hereinafter referred to as blooms, are semifinished steel products, hot rolled or forged to approximate cross-sectional dimensions. Blooms may be square, round, hexagonal, octagonal, or rectangular in section. For the purposes of this specification, minimum bloom section size will be 16 in. (103 cm ).

1.3 This specification covers two basic classifications of steel:

1.3.1 Class I -Vacuum-induction melted or consumable-electrode vacuum melted, or other suitable processes which will satisfy the quality requirements of this specification.

1.3.2 Class II -Air-melted vacuum degassed.

1.4 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.