HAYNES STELLITE ALLOY No. 21 is a cobalt-base alloy containing chromium and molybdenum. It is resistant to oxidizing and reducing atmospheres up to 2100 F. It has excellent strength at elevated temperatures that is maintained through aging characteristics occurring in the temperature range of 1300 F to 2100 F. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as creep, deformation, and fatigue. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: Co-1. Producer or source: Haynes Stellite Company.