GMNA GM292M PDF

This specification covers 2 grades of special quality of round and ovate chrome silicon steel wire intended for the manufacture of valve springs requiring resistance to set when used at moderately elevated temperatures and high stress levels. This wire shall be in the oil-tempered condition as specified by the purchaser.

Grade I steel shall be made by the electric furnace, open hearth, or basic oxygen process. The steel may be either ingot or strand cast. This valve spring quality material is not considered super clean steel.

Grade II steel shall be made by the electric furnace, open hearth, or basic oxygen process. The steel shall be strand cast. The subsequent refining processes must include use of secondary ladle refining and use of silicon for deoxidation purposes. Resulting inclusions thus shall predominantly be of a deformable nature. This material is considered super clean steel.