The steel may be made by any of the following processes: open-hearth, basic-oxygen, electric-furnace, vacuum arc remelt (VAR), or electroslag remelt (ESR).
Except for Grade A steel up to and including 12.5 mm in thickness, rimming-type steels shall not be applied.
Grades AH32 and AH36 shapes through 426 lb/ft, and plates up to 12.5 mm in thickness may be semi-killed, in which case the 0.10 % minimum silicon does not apply.
Besides few exceptions Grades D, DS, CS, E, DH32, DH36, EH32, and EH36 shall be made using a fine grain practice. For ordinary strength grades, aluminum shall be used to obtain grain refinement. For high strength grades, aluminum, vanadium, or columbium (niobium) may be used for grain refinement.
Grade D material 35 mm and under in thickness, at the option of the manufacturer, may be semi-killed and exempt from the fine austenitic grain size.
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