Black Oxide is a chemical conversion coating that penetrates approximately two to three millionths of an inch into steel surfaces. This makes Black Oxide an ideal finish for machined parts with close tolerances. The process creates a deep, black surface with corrosion resistant properties that are enhanced with the addition of a water displacing, oil topcoat. Commonly used on firearms, Black Oxide is both a protective and cosmetic finish for hand tools, automotive parts and machine tools. GunBlack can Black Oxide steel up to 16' long and process up to 15,000 pounds each day to meet customer demands. With the largest black oxide capacity in the northeast United States, GunBlack has large and small volume customers from Kentucky to Maine.