Black Oxide (Type 1) Military Standard, also known as “blackening” or “bluing,” is a surface treatment process that forms a thin, corrosion-resistant oxide layer on metal components. When performed according to Military Standard MIL-DTL-13924, Type 1 black oxide provides excellent protection against rust and corrosion while maintaining the base metal’s mechanical properties and appearance. This treatment is especially useful for parts exposed to harsh environments or outdoor exposure. Black oxide Type 1 is a chemical conversion coating typically applied to ferrous metals (such as steel and iron) through a controlled oxidation process. The result is a thin black oxide coating that increases the resistance to corrosion and wear. This process is commonly specified in the military and aerospace industries to meet stringent standards for corrosion resistance and durability in critical applications.
The black oxide coating produced under MIL-DTL-13924 is characterized by a uniform, durable finish that offers enhanced protection against oxidation and corrosion while improving the overall appearance of metal components. The treatment is often followed by an oil or wax application to further enhance the corrosion resistance and provide a lubricating effect.

Benefits

• Black oxide Type 1 is created by immersing steel or iron components in an alkaline solution, resulting in a conversion of the metal surface into iron oxide (Fe₃O₄), which is a stable and corrosion-resistant layer which provides excellent protection against rust and corrosion, particularly in humid, marine, or harsh environmental conditions.
• The black oxide coating is thin (less than 1 micrometer) and does not significantly alter the dimensions or tolerances of the component.
• Produces a uniform, matte black finish that improves the visual appearance of parts, providing a clean and professional look.
• When combined with a rust-preventive oil or wax, black oxide Type 1 enhances lubrication, reducing friction and wear on moving parts.
• The treatment meets the strict requirements of MIL-DTL-13924, ensuring high-quality, consistent results.