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Re: Slip-Critical Connections in Stainless Steel

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Are there bolts and tightening rules for slip-critical connections using stainless steel?
 
AFAIK, there's nothing recognized in the 'structural market' for such connections.  However, it is somewhat common for similar types of connections (with limitations) to be designed by OEMs.  Thus, firms like Polaris, Mercury Marine, Electric Boat, or Arctic Cat are quite competent in non-ferrous bolting. 
 
Determination of slip-coefficients can be done using material representing that intended to be used.  
 
The real trick is the bolting itself.  It's a challenge on many fronts.  First, reliable tightening of S/S bolts into yield as is done with A325 or A490 is not generally practical.   Even determining the 'yield point' is not a simple matter with the unique response one sees of these materials to stress.  Thus, typical target tensions for the most common bolting materials (ASTM F593) are only 75% of proof-load. 
 
Most tightening is done by 'Torque-Control', and a small proportion is done using S/S 'Tension Indicating Washers'.  The torque control method is hampered by factors new to persons with mainly structural bolting experience:  Things like galling or nut stripping -- and relaxation.  The Tension Indicator method is hindered by the fact that we are the only source for S/S DTIs --- and we don't yet carry all the sizes.
 
You may wish to consider contacting Robbins Stainless in Fall River, MA.  They have as much S/S bolting knowledge as anyone worldwide.  Their VP, Joe DeCosta, is Chairman of our ASTM Non-Ferrous Bolting Committee --- and a very nice fellow.  (Then again, all 'bolting guys' are nice)
 
Joe may be reached at (508) 675-2555.
 
David Sharp
TurnaSure LLC
57 E. 11th St. 8th Fl.
New York, NY 10003
(646) 602-1405