Boronizing is the diffusion of boron into a metal workpiece to form an extremely hard (1400-2000HV), well anchored protective layer. The service life of a part or machine subject to abrasive, erosive, or corrosive wear may be extended by boronizing.

Boronized layer (ie.008") Boron diffusion zone (ie.016" below boronized layer) Substratum (steel)