This Standard specifies the size, shape, weight, tolerances, technical requirements, test methods, inspection rules, package, marking and quality certificate for alloy structure steels of hot rolling and forging. This Standard is applicable to the alloy structure steel bars with the diameter or thickness no more than 250 mm. After the negotiation between the supplier and acquirer, the alloy structure steel bars with the diameter or thickness more than 250 mm may also be supplied. The chemical components of the grades specified in this Standard are also applicable to steel ingots, billets and their products.

Replaced by GB/T 3077-2015