Bolt elongation with torque 1

[fastech]

Does anyone know of a set of tables available or a formula that will aid in determining approximate stretch in various grade and size bolts at the ultimate tensile point? I have a found an interesting table in the

http://www.itw.com

website that goes up to 1/4-20 but I am interested in 1/4 up. I understand that there are many variables involved here but one has to often make assumptions regarding the K factor when torquing said bolt/s. The KISS formula always helps(Keep It Short & Simple) Bill P.
CSFT, Inc.

 

[Grunchy]

Elastic stress divided by E would be elastic strain.

You have to get strain at UTS from the manufacturer or some reputable source. You can't just divide Young's modulus by UTS to determine failure strain because UTS is beyond the elastic regime.

Of course, remember that UTS in the threaded portion causes lower stress in an unthreaded shank (if your bolts have an unthreaded portion).