This specification covers cast carbon and alloy steel ingots and strand castings, semi-wrought ingots and strand castings, and rolled or forged blooms, billets, and slabs for steel forging stock. Materials shall be manufactured and furnished in a condition that can withstand, for an indefinite time, exposure to all climatic conditions without developing any external or internal cracks. Final products shall be free of injurious surface imperfections. If, however, such defects do occur, surface conditioning, cutting, or parting may be performed by scarfing or flame-cutting. Heat and product analyses shall be carried out to evaluate conformance of steel specimens to chemical composition requirements.

1.1 This specification covers cast carbon and alloy steel ingots and strand castings, semi-wrought ingots and strand castings and rolled or forged blooms, billets, and slabs for forging.

1.2 Blooms, billets, and slabs are semi-finished steel products, hot rolled or forged to approximate cross-sectional dimensions. Blooms and billets may be square, round, octagonal, or rectangular in section; slabs are rectangular. Although no invariable rule prevails between the terms blooms and billets, and they are frequently used interchangeably, the following size distinctions are in general use.

1.2.1 Blooms—Cross-sectional area greater than 36 in.² [230 cm²].

1.2.2 Billets—Maximum cross-sectional area 36 in.² [230 cm²].

1.2.3 Slabs—Minimum thickness, 1¹/₂ in. [4 cm]; width, more than twice the thickness; and generally a cross-sectional area of not less than 16 in.² [100 cm²].

1.2.4 Ingots either top or bottom poured or secondary remelted are covered.

1.2.5 Strand castings with or without additional reduction are covered.

1.3 Supplementary Requirements (S1 to S19) of an optional nature are provided. They shall apply only when specified by the purchaser.

1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.5 Unless the order specifies the “M” specification, the material shall be furnished to the inch-pound units.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.