Normalizing is a heat treatment process in which steel components are heated above their critical transformation temperature and then cooled in still air under controlled conditions. This process refines the grain structure, removes the effects of previous thermal or mechanical processing and produces a more uniform microstructure throughout the material. Unlike annealing, which uses slow furnace cooling to maximize softness, normalizing uses air cooling to achieve higher strength and hardness while maintaining good ductility and machinability.

Normalizing is commonly performed on forgings, castings and welded components before machining or final heat treatment to improve consistency and mechanical performance.