About 410|The basic martensitic stainless. 12% chromium with enough carbon to harden by heat treatment. In the annealed condition it machines reasonably well and significantly easier than
304 since it doesn't work-harden as aggressively. Can be hardened to HRC 40+ for wear resistance. Used for valve components, pump shafts, bushings, cutlery, and turbine blades. The corrosion resistance is modest, adequate for mild environments but not chemical or marine service. Magnetic in all conditions. Welds with preheat and post-weld stress relief. Compare to
416 (sulfur added for better machinability) and
420 (more carbon, higher hardness).
