Pardon me on this subject, I beg to differ with you. These parts such as the hand, hammer,trigger and bolt stop all started off as soft parts. They are fitted as soft parts with files and such, then heat treated either case hardening or being heat hardened and tempered. If case hardened the surface is hard with a softer core. If the part is a tool steel and is tempered properly it is hard all the way through. Where the problem comes in is if the right temperature is missed during the tempering the part is either too hard or not hard enough. So if it's too hard it becomes brittle and can shatter. Most of the Italian pistol parts I have dealt with have been mild steel that was case hardened. If these parts are not re hardened the wear on them is much faster.