orque conversion to bolt tension
 

torque conversion to bolt tension
ok, so a while back, i wrote a formula in my green bible er, i mean book, that i had come across. unfortunately, what i didn't do was write down the resource. most people would say it's bogus, b/c there are so many variables involved, but when the contractor is looking for a number for tensioning anchor bolts, it comes in handy:
t = 0.2fd
where f is the required tension in the bolt, and d is the bolt diameter.
i thought i had gotten it from blodgett, but i can't find it.
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yeah, don't start will on the subject ... sorry, will, just good natured ribbing ...
your formula is what i have stored in my memory banks as a typical ball-park answer to a complex question.
"mechanical engineering" magazine, october 1983, "designing with threaded fasteners" by girard haviland.
t=kdf
t (in-lb)
d nominal diameter in inches
f force in bolt
k constant (usually 20%)
there's a lot more to the article, but i only read as far as that formula.
thanks for the response guys! in case any one was wondering, i came across this literature. i really like their caveat at the end. think i need to incorporate it somehow!
for what it's worth, i have some old references.
the first sheet is a table developed at a local industry.
the second is part of a 20 page treatise on bolts. i got both of these from my father-in-law, a mechanical engineer who was an expert on bolts. these are 40 years old.
the third and fourth sheets, i derived for my own use, probably with his help. they simply solve for the statics of the bolt geometry.
for what it's worth, i have the following written in my asd (although i negelected to reference the source):
t = (0.15*d*f)
that's for well lubricated bolts, but it jumps from 0.15 to 0.35 for bolts w/o lubrication.