Valve, Black Diamond™ Stainless, 4.0mm Stem x 32.00mm Head Dia. Blank

The Proprietary Black Diamond™ process is not a coating. It penetrates and treats the steel to a depth of .002”, so it can never peel or flake off. Coatings such as chrome are “surface build ups” that rely on adhesion to remain intact. They can crack, peel, and flake off, depositing abrasive debris in the guide, causing wear and seizure. The Black Diamond™ process creates an extremely hard and smooth finish, preventing accelerated wear on the stem and keeper groove areas. This hard smooth finish has a low coefficient of friction, making it less aggressive on the valve guide, and promoting longer guide life. In exhaust environments, the Black Diamond™ process offers increased resistance to corrosion which is critical for long life.