The thickness of coating is almost negligible at about 0.000030 inch. Black Oxide coating has an ability to absorb a subsequent coating of oil or other corrosion inhibitor. Of the many options open to any component designer, black coating has served its purpose extremely well over the years and will continue to be important to the metal working industry.

Present-day propriety black oxide baths not only contain an alkaline base with oxidizing agents, but activators to increase the blackening rate at lower temperatures and to produce more uniform results. Black oxide baths now contain additives that increase corrosion and abrasion resistance.

A black oxide finish offers a combination of properties that cannot be provided any other way. This conversion coating does not change the dimensional, physical or mechanical properties of the surface treated. The finish is inexpensive and easy to apply. It has an excellent appearance and is abrasion resistant. Corrosion resistance is satisfactory for a wide variety of applications.