Black Oxide Coating Service
RPS provides professional black oxide coating services for custom precision parts, delivering high-quality surface protection solutions. With advanced blackening production lines and strict quality control systems, we ensure every part achieves excellent performance in corrosion resistance, appearance, and durability.
What is Black Oxide?
Black oxide (also called blackening) is a chemical surface treatment that creates a thin black oxide layer on the surface of metals. This process improves corrosion resistance and enhances appearance. Black oxide is commonly applied to carbon steels, alloy steels, tool steels, and some stainless steels, making it a popular solution for industrial and mechanical components.
Why Choose Black Oxide?
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Improved Corrosion Resistance – Prevents rusting in humid or oxidizing environments
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Reduced Light Reflection – Matte black finish suitable for optical and instrument parts
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Enhanced Surface Hardness – Slightly increases wear resistance
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Dimensional Stability – Extremely thin layer (≤1μm), with no impact on precision tolerances
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Cost-Effective – More economical than plating or painting, suitable for large-volume production
Black Oxide Surface Treatment Parameters
| Parameter | Typical Range / Notes |
|---|---|
| Color | Black, Dark Gray |
| Gloss | Matte / Semi-Matte |
| Coating Thickness | ≤ 1 μm, negligible dimensional change |
| Surface Roughness | Ra 0.8–1.6 μm (depends on base material) |
| Surface Hardness | Slightly increased, base-material dependent |
| Wear Resistance | Moderate, suitable for medium to low-friction parts |
| Corrosion Resistance | Can be enhanced with oil impregnation |
| Appearance Uniformity | Consistent black finish, minimal color variation |
Example of Black Oxide Parts
What Materials Can Be Black Oxide Coated?
| Material Type | Grades / Examples |
|---|---|
| Carbon Steel | 1018, 1045, Q235, 20#, 45# |
| Alloy Steel | 4140, 4340, 40Cr, 42CrMo |
| Tool Steel | D2, O1, H13, SKD11 |
| Stainless Steel (Martensitic Preferred) | 410, 416, 420, 430 |
Where is Black Oxide Used?
Our black oxide services are widely used in different industries, including:
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Machinery – gears, shafts, bolts, precision tools
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Automotive – brake system parts, engine fasteners, components
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Military & Optical Instruments – firearm components, optical housings, measuring instruments
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Electronics – anti-glare housings, connectors, casings
