Is the Passivation of SST Hex Screws/Bolts per ASME SA-193 Standard?

[beh188]

Is it typical for stainless steel hex screws/bolts manufactured per ASME SA-193 to be passivateed? The standard does not specify performing passivation. Neither does ASTM A-962 referenced by this standard.

 

[TVP]

Yes, it is typical for stainless steel fasteners to be passivated. You are correct that neither ASTM A962 nor ASTM A193 specify this as a requirement. It is up to the end user to specify the appropriate surface treatment based on the end use, environmental conditions, etc.

 

[Bluecat46]

Question

Does a Stainless Steel fastener thats been passivated, have the same chance that when torque is applied that threads end up 'galling' or does the passivate help in preventing that.

If so which surface treatment is the best at reducing this 'galling' affect?

 

[SJones]

http://www.assda.asn.au/images/PDFs/faq no5 galling.pdf

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04