One-piece stainless-steel, stellite-tipped valves impregnated by a special nitrided process with .002" depth and .0002" surface buildup to improve wear properties and reduce friction This process provides resistance to corrosion; wears superior to hard chromium and electrolysis nickel-plating Lightweight with profiles that provide excellent flow characteristics Compatible with leaded and unleaded fuels and can be run in cast iron- and bronze-type guides at close tolerances for maximum oil control and heat dissipation Made in the U.S.A.. NITRIDE VALV EXH PN,SH-84