Mike Besemer (WM4B) wrote:
>>From http://www.estainlesssteel.com/gallingofstainless.html...
>
>
>"Thread galling seems to be the most prevalent with fasteners made of
>stainless steel, aluminum, titanium, and other alloys which
>self-generate an oxide surface film for corrosion protection. During
>fastener tightening, as pressure builds between the contacting and
>sliding thread surfaces, protective oxides are broken, possibly wiped
>off, and interface metal high points shear or lock together. This
>cumulative clogging-shearing-locking action causes increasing adhesion.
>In the extreme, galling leads to seizing - the actual freezing together
>threads. If tightening is continued, the fastener can be twisted off or
>its threads ripped out."
>
>I always use an anti-seize compound on stainless hardware.
>
I've never felt comfortable about using oil- or grease-based materials
on threads that are supposed to stay tight afterwards.
A lesser-known feature of Loctite and similar thread locking fluids is
that they also prevent galling when the nuts are being tightened. I've
always had good success with the "blue" Loctite grades like 242 which
are designed to be released with hand tools. SS nuts tighten up smoothly
and the galling doesn't happen.
--
73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek
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