Hard Black Anodizing
Type III HBA
Military-grade Type III hard anodizing for high-stress aerospace, defence, and semiconductor components.
Hard Black Anodizing (HBA) is a specialised Type III anodizing process that produces an exceptionally dense, wear-resistant, and light-absorbing black oxide layer on aluminium components. It is widely specified for defence optics, semiconductor wafer handling equipment, and aerospace structural parts.
The process creates a hardness of up to HV 500, rivalling hard chrome plating, while maintaining dimensional stability. The non-reflective black finish is critical for optical assemblies and night-vision equipment.
Active Treatment performs HBA in a controlled bath with precise temperature and current-density management to ensure uniform layer thickness across complex geometries.
Key Benefits
- Extreme hardness up to HV 500
- Non-reflective, low-light-scatter black finish
- Excellent dielectric properties
- Superior wear and abrasion resistance
- Passes MIL-A-8625F Type III specification
Specifications
| Hardness | HV 400–500 |
|---|---|
| Standard | MIL-A-8625F Type III |
| Substrate | 6061-T6, 7075-T6 preferred |
| Thickness | 25–75 µm |
| Surface roughness increase | ~12–15 µm Ra |
Frequently Asked Questions
What standard does your Hard Black Anodizing comply with?
Our HBA process is performed to MIL-A-8625F Type III, the US military specification for hard anodize. We can provide documentation on request.
Why does hard anodizing slightly roughen the surface?
The anodic oxide layer grows both inward and outward from the original surface. The outward growth (approximately 50% of total thickness) increases surface roughness by roughly 12–15 µm Ra. Critical surfaces may require post-anodize lapping.
Can HBA be applied to 7075 aluminium?
Yes. 7075-T6 is commonly hard-anodized for aerospace applications. However, the high zinc content may slightly affect colour uniformity. We recommend confirming requirements before production runs.
How does HBA compare to hard chrome plating?
Both achieve similar hardness (HV 400–1000 for chrome vs. HV 400–500 for HBA). HBA is preferred where weight is critical (oxide is lighter than chrome) and where hexavalent chrome-free processes are mandated by environmental regulations.
Is Hard Black Anodizing RoHS compliant?
Yes. Unlike hexavalent chrome processes, hard anodizing uses no hazardous heavy metals and is fully RoHS and REACH compliant.
Request a Quote
Contact Active Treatment Pte Ltd in Singapore for Hard Black Anodizing. Call +65 6352 9846 or email activetreatment88@yahoo.com.sg.