Atmospheric oxidizing is utilized to produce a black corrosion resistant surface film of iron oxide. Beneath the iron nitride layer is a nitrogen-enriched hardened diffusion zone. Flakes and slivers will destroy seals and glands. Plating creates pits and has inherent adhesion problems. Chrome plating is environmentally hazardous.
Chrome lacks dimensional uniformity.
Super corrosion resistance. Improved wear resistance. Better lubrication retention. Dent resistance without induction hardening. No surface pitting, flaking, or hydrogen embrittlement.