What is Black Oxide or Blackening | Junying Custom Metal Finishing Services


Browse Junying custom metal finishing services for precision CNC machining parts, here CNClathing.com will bring you the black oxide or blackening definition, common types, applications, and benefits.


What is Black Oxide or Blackening?

Black Oxide treatment, also known as blackening or gun bluing, is a chemical process of forming a black conversion coating on stainless steel, copper and copper based alloys, zinc, powdered metals, silver solder, and ferrous materials, to improve corrosion resistance and minimize light reflection. Immerse the black oxide parts in the oil or wax, maximal corrosion resistance can be achieved. It has minimal buildup compared to other coatings. Unlike electroplating, the black oxide coating is the black iron oxide, magnetite produced by a chemical reaction between the iron of the metal and oxidizing salts in the hot oxide solution, there is obvious dimensional change.


Black Oxide Types

– Hot black oxide
– Mid-temperature black oxide
– Cold black oxide

Black Oxide Applications

  • 1. Military components
  • 2. Medical and surgical instruments
  • 3. Architectural hardware and assemblies
  • 4. Automotive cans and fasteners
  • 5. Store displays and fixtures
  • 6. Electrical wire strippers, gears
  • 7. Gun components, shell magazines


Benefits of Black Oxide

  • 1. Dimensional stability. The size of the metal to be treated will not change.
  • 2. Protection. The appearance, abrasion resistance, and corrosion resistance have been improved.
  • 3. Productivity. A large batch of metal blackening can be done in one time, which saves time and cost greatly.
  • 4. Durability. The black oxide finish will not drop, chip, crack or rub off, only can be removed by mechanically or chemically methods.
  • 5. Cost-effectiveness. Cheaper than similar corrosion protection options like painting and electroplating.
  • 6. Enhanced lubrication and anti-galling characteristics with oil or wax finish.
  • 7. Do not affect the luster of the metal parts.