Aerospace Metals is pleased to offer black oxide processing. Black Oxide is a conversion coating for ferrous materials, stainless steel, copper as well as copper based alloys, powdered metals, zinc, and silver solder which results in a black color. Black oxide is used to achieve mild corrosion resistance. It is also used to enhance appearance and minimize light reflection.

In order to reach maximal corrosion resistance, the addition of oil or wax must infiltrate the black oxide. The black coating allows retention of the original surface properties as well. These properties include the gloss from polishing and/or rockwell hardness from heat treating.

Untreated parts are capable of withstanding salt spray tests with a maximum of 96 hours.

Advantages of black oxide processing include:

  • No dimensional changes (.000005 thick)
  • No chipping
  • Absorbable to wax and oils
  • Heat Survivability (up to 900 Degrees F)
  • Adaptability to a wide variety of applications
  • Minimal buildup

Additionally, black oxide is beneficial because this process enhances thickness to steel parts. Even though the thickness may be microscopic, it allows for maintenance of the sharpness of tools such as drills or screwdrivers. Also it helps minimize corrosion and friction due to the presence of oil or wax. The oil and/or wax not only assists in that beneficial aspect, but also allows for the material to be resistant to water.

How Long Does Black Oxide Last?

Black Oxide can last up to 100 hours of neutral salt spray (ASTM B117) or several hundred hours of humidity (ASTM D1748) – all dependent on the sealant utilized. A sealant of some sort is requisite to black oxide finishes due to the porous crystal structure of the black finish itself.

Please call 800.398.0790 or email us at for further inquiry and a free quote today. We would love to discuss our capabilities and why our customers trust us with excellent service and competitive turnaround times.