Passivation
What is Passivation?
Passivation is a term for a variety of processes that make a metal or other substance unreactive, or passive, by altering the surface layer or coating the surface with a thin inert layer. Because ferrous metals flake when oxidized (e.g. rusts), anodizing is not an appropriate protection technique.
As a result, passivation is most commonly used for ferrous parts, especially stainless steel. For ferrous metals passivation removes free iron molecules embedded in the surface of the part and leaves a protective coating which protects the underlying material.

Properties and Benefits
- Prevents rust formation on ferrous parts, including stainless steel
- Prepares surface for other finishes, including priming and painting
- Reduces / prevents reactivity to other parts

Specs & Certifications
- QQ-P-35 --- NADCAP Approved, ROHS Compliant
- AMS-QQ-P-35 --- NADCAP Approved, ROHS Compliant
- FED-QQ-P-35 --- NADCAP Approved, ROHS Compliant
- AMS-2700 --- NADCAP Approved, ROHS Compliant
- ASTM A380 --- NADCAP Approved, ROHS Compliant
- ASTM A967 --- NADCAP Approved, ROHS Compliant
- ASTM B912 (Electropolish & Passivate) --- ROHS Compliant
- ASTM F8 --- ROHS Compliant
- MIL-C-13924 (Black Oxide Coating)
- MIL-DTL-13924 (Black Oxide Coating)

Applications / Industries
- Aerospace
- Architectural, including Marine Architecture
- Food Preparation, Processing and Handling
- Medical
- Military
Unique Substrates
In addition to our Passivation services, AOTCO plates and anodizes many exotic and uncommon Substrates that most plating providers won’t or can’t do. Please click to see a list of the Substrates we commonly plate.
Contact Us
If you’ve got a question about plating or other surface finishing, please reach out and speak with our experts to see how AOTCO can best help you.