Torque conversion to Bolt Tension 2

[ChipB]

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.

 

[rb1957]

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.

 

[JedClampett]

"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.

 

[ChipB]

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!

 

[miecz]

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.

 

[JoshPlumSE]

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.