When you heat treat metal Temp time at the temp and cooling process makes metal softer or harder. My first job was working in heat treatment They made starter ring gears. The metal cam in soft enough for coiling and cutting After but welding it was heat treated again after milling it was heat treated again. They then press flat and the teeth were heat treated again Only the last heat treatment was for hardness. The others were all for keeping the metal soft an uniform . Stainless is a different metal and the process is different. If you want to know about metals and the different process Look it up on the inter net under metals ;D ;D ;D LarryJRS said:True Larry. And the reasons for heat treating produce the same results. Hardening and strengthening. Not softening.