Nitric passivation
Nitric passivation clears free iron off stainless steel so the passive layer can re-form. It adds no plated layer. Olymco, Inc., in Canton, Ohio, provides the nitric process. Send the governing specification and required acceptance test with your part details.
When does a stainless part need passivation?
Stainless parts may require passivation after machining, forming, or other handling that introduces surface contamination. Use the drawing or customer requirement to define the treatment and test, particularly when the part belongs to a controlled manufacturing program.
Passivation is a chemical surface treatment. In nitric passivation, the cleaned part is immersed in a nitric acid bath that dissolves free iron without meaningfully attacking the stainless. It does not add a plated layer or repair damage in the base metal. The alloy, incoming condition, and specified method determine what needs review.
Describe machining residue, oil, scale, weld heat tint, or visible rust. These conditions may require preparation beyond passivation, so they belong in the initial request.
Identify non-stainless components, existing coatings, or features that need special handling. Mention available drawings and call (330) 452-2300 to arrange how to share them.
For stainless manifolds, tubing, and fittings in liquid cooling loops, see passivation and electropolishing for liquid cooling components.
Six details to specify for a quote
- Material and substrate
- Send the exact stainless grade and its heat treatment condition.
- Finish variant
- Name the specification number and the required nitric method.
- Part size limits
- Send dimensions, weight, and every material present in an assembly.
- Tolerances
- Identify critical dimensions and any cosmetic requirement.
- Volume range
- State the quantity per lot.
- Minimum order
- Ask about the minimum order for your job.
Questions buyers ask about this process
Does passivation add a coating?
No. It is a surface treatment that removes free iron contamination from stainless steel. If your drawing requires a deposited finish, identify that requirement separately.
Does passivation remove weld heat tint or scale?
Do not assume it will. Heat tint and scale may need separate preparation. Describe the incoming condition and confirm the required work with Olymco before shipping parts.
Can I substitute nitric for a specified citric process?
Only if the governing requirement permits the change. Olymco provides nitric passivation. Provide the specified method and obtain confirmation before treating a different process as acceptable.
Will passivation repair rust damage?
It does not restore metal lost to pitting or corrosion. Describe the damage and the stainless grade so the treatment can be assessed for the actual condition.
Will dimensions or appearance change?
Passivation is not intended to provide dimensional build or a polished appearance. Identify critical dimensions and cosmetic requirements, and confirm suitability for the alloy and incoming condition.
Is electropolishing the same as passivation?
No. Electropolishing removes metal to refine the surface; passivation addresses surface contamination. Provide both callouts if your print requires both, and confirm the applicable treatment and tests.
Related finishes
Get a quote for your part
Have the six details above ready when you request a quote.