Possible galling between 18.8 S/S and 303 S/S

[dragonsaver]

We are looking at a new design of one of our products. We normally use 18.8 S/S bolt on the handle. It is treaded into a valve top which now has a 303 S/S insert. When there is a load placed on the valve and the handle is tightened to set the pressure, you can 'feel' a binding. When the threaded handle was removed, there were metal filings inside the top.
Question is should the insert be 18-8, or another material? Is this a problem with the softness of the material? Any suggestions?

 

[israelkk]

Galling in stainless steels is common. Is the insert a standard one or custom made? If it is a standard one you may try to find one with silver coating from the same manufacturer.

 

[Metalguy]

If you change one or both parts to something like Nitronic 60 stainless, it probably won't gall.

 

[LBlount]

Change the surface characteristics see thread: thread307-69863