15-5 Stainless is a precipitation hardening material like 17-4. It’s name comes from the 15% chromium and 5% nickel chemical makeup of the alloy. 15-5 is best known for it’s corrosion resistance and it’s ability to stand up to stringent atmospheric conditions. In essence, it was created to yield higher mechanical properties and provide greater toughness than the more common 17-4 stainless.
15-5 Stainless is a modification of 17-4 PH Stainless. Both display physical properties of great tensile strength and mild corrosive resistance. These properties are preserved at temperatures at up to 600°F. 15-5 stainless is formed with better toughness than 17-4.
15-5 primarily comes in the annealed state and can be heat treated/aged at lower temperatures to enhance the mechanical properties and durability even further.