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Reworking Passivated Parts
What is the effective depth of QQ-P-35C [link is to free spec at Defense Logistics Agency, dla.mil] Passivation? I have some threaded parts from a vendor that look to have been threaded with a roll tap. Based on a visual inspection of the threads, I suspect that an oversize tap drill was used. We've been breaking screws off in the holes. The parts have been pressed into the Next Higher Assembly which can't be exposed to acids, etc. The easy solution is to re-tap the threads with a cutting tap, but I'm worried about exposing corrodible material. The final assembly will be exposed to a salt fog environment. What to do?
The material is 304 CRES.Ulrich von Erfurt
- North Merrick, New York USA
Typical passivation layer is 20-30 Angstroms thick only. The thickness is dependent partially on the method used to passivate.
Stellar Solutions, Inc.