Nitriding - Adding nitrogen to iron-base alloys by heating the metal in contact with ammonia gas, or other suitable nitrogenous material. Nitriding is conducted at a temperature usually in the range of 935-1000” F. and produces surface hardening of the metal without quenching.

Non-Ferrous - Metals or alloys that contain no appreciable quantity of iron. This term is applied to such metals as  aluminum, copper, magnesium, etc.

Normalizing - See heat treating definitions page 146 through 148.