Citric and nitric acid processes available
Removes free iron and weld contamination
Restores chromium oxide passivity
Performed after machining and welding
Certified to ASTM A967 and A380
Improves performance in food and medical use
| Stainless 304 and 316 |
| Stainless 17-4 PH |
| Duplex stainless |
| Machined and welded stainless assemblies |
| Medical-grade stainless parts |
| Specification | Details |
|---|---|
| Standards | ASTM A967, ASTM A380 |
| Process | Citric or nitric acid |
| Materials | 300 series and 400 series stainless |
| Thickness change | None |
| Testing | Copper sulphate and ferroxyl tests |
| Lead time | 3–6 working days |
Followed by cleaning and packing
Combined with electropolishing
Certification documented
Welding burns chromium away from the surface and leaves scale and iron contamination, both of which become corrosion initiation sites. Passivation removes them and restores the protective layer.
Citric is safer to handle and increasingly preferred, while nitric is specified in some aerospace and nuclear standards. We select according to your specification.
No. It removes only surface contamination, leaving dimensions and appearance unchanged, which is why it is safe on finished precision parts.
Type II and Type III anodizing for aluminium: clear, black and colour finishes with improved corrosion and wear resistance, thickness from 5 to 50 µm.
Type III hard anodizing builds a 25-50 µm ceramic-like oxide layer with up to 500 HV surface hardness for wear-critical aluminium parts.
Glass bead blasting for a uniform satin finish on metal and plastic parts. Hides tool marks, prepares surfaces for coating and gives a premium matte look.
Sand blasting for surface cleaning, descaling and roughening. Removes rust, scale, old coating and oxide before welding, painting or bonding.
Mechanical polishing to mirror and optical finishes: Ra down to 0.05 µm for mould cavities, light guides, medical parts and decorative surfaces.
Send your files today — DFM-checked quotation within 24 hours.