Stainless steel passivation
Nitric acid passivation of stainless steel parts after machining or fabrication. It removes free iron from the surface so the steel's own protective layer can re-form.
- Finish
- Stainless steel passivation
What passivation does
Stainless steel resists corrosion because chromium in the steel forms a very thin oxide layer on the surface. Machining, grinding and handling leave particles of free iron on the surface, which rust and stop that layer from forming properly.
We clean the parts and then treat them in nitric acid, which dissolves the free iron without attacking the stainless steel. The protective layer then re-forms evenly. Passivation is not a coating: it does not change the part's colour or dimensions.
We do not carry out passivation verification tests, such as salt spray or copper sulphate. If your drawing requires one, tell us in your enquiry.
What to put on your drawing or enquiry
- Stainless steel grade, for example 304, 316 or 410
- The specification, if your drawing names one. Nitric treatments are listed in ASTM A967 and SAE AMS 2700 (Method 1)
- Quantity per lot and expected yearly volume
Also consider
Email your drawing for a quote
Attach the drawing and include as much of this list as you can. The more you send, the fewer questions we need to ask before quoting.
- Drawing: PDF, DWG, DXF or STEP
- Base material and grade
- Finish, and thickness in µm
- Quantity per lot and yearly volume
- Areas to mask, if any
- Standard or customer specification