This specification covers a corrosion resistant steel in the form of investment castings. These castings have been used typically for parts requiring hardness up to 58 HRC and having resistance to corrosion and to wear, but usage is not limited to such applications. Optimum corrosion resistance is obtained by hardening from 1850 to 1950 °F (1010 to 1066 °C) and tempering at not higher than 800 °F (427 °C).