This specification covers a corrosion and heat resistant steel in the form of investment castings. These castings have been used typically for parts requiring corrosion and heat resistance up to 800 degrees F (427 degrees C) especially when such parts are welded during fabrication, for parts requiring oxidation resistance up to 1500 degrees F (816 degrees C) but useful at that temperature only when stresses are low, and for parts requiring resistance to fuming nitric acid, but usage is not limited to such applications.