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Torque conversion to Bolt Tension
2

Torque conversion to Bolt Tension

Torque conversion to Bolt Tension

(OP)
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.

RE: Torque conversion to Bolt Tension

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.

RE: Torque conversion to Bolt Tension

"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.

RE: Torque conversion to Bolt Tension

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.

RE: Torque conversion to Bolt Tension

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.  
 

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