12Cr-8Ni-2.9Mo Stainless (var. 3)

This is a precipitation-hardened martensitic stainless steel with significant aluminum and cobalt additions, designed for high-strength applications requiring corrosion resistance and hardness. The composition—dominated by iron with 12% chromium, 8% nickel, and nearly 2.5% aluminum—positions it in the family of age-hardenable stainless steels, where the Al and Co promote strengthening through intermetallic precipitation. It is used in aerospace, defense, and high-performance industrial applications where a combination of corrosion resistance, elevated-temperature stability, and exceptional strength-to-weight ratio is critical, offering advantages over traditional austenitic stainless steels or lower-strength martensitic grades in demanding structural and component applications.