Another solution (in terms of stainless) is to use different grades to avoid
seizing threads. For eg. for our jacking screws on our PRVs we use 303 grade
stainless for the screw, which is screwed into a 316 head. This is a 5/8" UNF
thread that can sometimes be a constantly exposed to >2500lbsF and we used to
ship them out without anti seize grease as standard without a reported seizure.
Of course, adding anti seize grease is always a preferred option.
Troy
Sent from my iPad
On 6 Aug 2016, at 11:12 PM, Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx>
wrote:
On 8/6/2016 1:05 AM, Uwe Klein wrote:Stainless steel parts in sliding contact tend to "gall" (surface-to-surface
Am 05.08.2016 um 20:28 schrieb David Weinshenker / Henry Spencer:
Correct. Stainless fasteners, you can buy off the shelf.
We've ( actually a customer project I was involved in) had a PITA of a
problem with electropolished stainless item's threaded holes ( welded
nuts as well as machined threading ) and the corresponding stainless
screws. If ever a screw was binding even slightly during assembly
waiting a day or two and trying to remove them would be "unsuccesfull".
( torque the head off before it would move in the threads.)
Solution was coating the screws in a special process. ( don't have the
name at hand but can inquire.)
sticking leading to chatter quickly leading to extreme wear) if unlubricated,
or (if sliding contact is ongoing) even if lubricated with traditional
petroleum-based lubes.
The solution I've seen is teflon-based lubes.
Henry
