Weld Nut Load Ratings?

[Penguineer]

Hello All,

I have been searching for load ratings for various weld nut sizes. I feel like this information should be out there based on the nut size and the weld size, but I have so far been unsuccessful. If anyone has seen information like this, could you point me in the right direction? Ultimately I would like to determine an upper limit for tensile loads that can be applied to weld nuts before the weld is put at risk.

Thank you!

 

[Screwman1]

Weld nuts should be loaded so that the weld is under compression. The welds are simply to provide a 'self wrenching' feature and allow positioning and locating in blind or inaccessible locations.
Based on the variability of welds and fusion on weld nuts, I would not trust them in a tensile loaded condition.

 

[TVP]

Weld fasteners are typically tested to a minimum torque before failure, and a static push-off load. Here are some references with typical data:

http://www.twi-global.com/technical...-guidelines-for-projection-welding-weld-nuts/

http://www.pemnet.com/fastening_products/pdf/wndata.pdf

http://www.thefabricator.com/article/shopmanagement/projection-welding-for-nut-and-bolt-attachment

 

[tbuelna]

There are various forms of weld nuts. The most common are attached using a resistance weld. These weld nuts are typically made from steels that allow them to readily weld to common structural steels, so the nut threads usually have modest strength. The welds usually are only required to provide enough strength to hold the nut in place while the mating bolt is being tightened. Most weld nuts are only designed to carry tension loads once the bolt is installed and properly preloaded. The primary stress experienced on the weld joint of the weld nut is probably shear when the mating bolt is torqued.

 

[Duwe6]

". . .upper limit for tensile loads that can be applied to weld nuts before the weld is put at risk."

Unless you pull-test a LARGE sample, that allowable load approaches *zero*. If you want to try testing, I would suggest the sampeling rate amd methodology used in AWS D1.1 code for testing threaded anchor studs. Problem with that is that unless you find a *very* low failure rate, it would have been faster to have manually welded these nuts.