15-5 PH VM stainless steel is a martensitic precipitation-hardening stainless steel with approximately 15% Chromium and 5% Nickel, hence the name 15-5. Vacuum Consumable Electrode Remelting (VM) is the melt process used for Type 1. The VM material is a cleaner product offering lower percentages of ferrite. 15-5 has high strength, high hardness, and excellent corrosion resistance. 15-5 materials forgeability is superior to 17-4. Strength can be further increased by a single low temperature heat treatment. (UNS:S15500)