440c steel comes with a Rockwell hardness of 57 to 58 HRC, which is considered quite hard. Heat uniformly at 840 to 875°C temperature if you want to anneal 440 stainless steel. After heating, soak and coal the steel quite slowly in the furnace. In contrast, heat at 1010 to 1070°C temperature if you want to harden 440c stainless steel. Keep in mind that you fully soak and quench in warm oil or air cool when you are hardened 440c steel. However, be careful not to overheat the 440c steel, as full hardness will not be obtained.