Welding a nut into thin-wall steel

[Sodo]

Here's a way I figgered out to weld a small nut into thinwall (3/8 nut into .065") steel tubing.

Drill a hole about the size of the wrench. For example for a 3/8" nut, which uses a 9/16" wrench, drill a 9/16" hole.

With a cold chisel, cut the six corners

Pound the nut into the hole flush, and weld it up.

Sorry forgot to take a pic of it welded and now it's all "somewhere else". But at this point you know what to do.

 

[bcp]

I'm too lazy.

What I would do:

Light duty-weld a T-nut into the hole.

For heavy duty, I would double-nut it on the end of a bolt, grind the nut round, then weld it into the hole

Bruce

 

[Sodo]

Cutting those six corners is easy, fast. And it holds the nut for welding. Agreed, chisels are old-school. The only thing about this method that might be a challenge is drilling the right size hole.

For a 3/8" nut I don't think you want to grind away any metal, you need all you can get. I found a finished pic.

 

[Ed of all trades]

Sodo
Thanks for the tip might just come in handy some time. Ed

 

[stingray1]

Thanks for the tip,I'll give this a try next time I need to weld one up.

 

[Sodo]

Here's a pic of where it's used. It's for a wingnut to hold a spreader to prevent bending the cutting edge on a "bucket spade". Bucket spade is just 7" channel with some brackets to be held on by a cargo strap.

Spreader bar slides in behind the bucket spade and there's a hole in the channel for the wing-bolt.

 

[Gary Fowler]

Unless there is some reason for the nut to be counter sunk, I would have just welded around it while it is setting flush on top of the channel. I have welded hundred of nuts onto steel and pipe this way and never had a problem with the threads or the nut breaking off.

 

[Sodo]

Gary I've done that too but this application is a thinwall sq tube.

I could have reversed it where the nut was external on the 7" channel (the spade) and wingbolt tightened from inside the bucket. But I have a 9/16" holecutter & (rotabroach) which is high technology modern tool on a battery-powered drill so had to balance it with an old-school hammer & chisel. Can't really call the MIG part modern technology. Hard to believe I learned to MIG on the farm in 1980 (36 years ago). :shocked:

 

[Renze]

For that use, there is a Kalei nut, or press nut.
Press nuts | Fabory Web Shop

 

[flyerdan]

The riv-nuts would have to be installed from inside the tube to keep it from pulling out, and might wallow out its mounting hole in this application.
I've always rounded nuts off in the drill press with an angle grinder to put in tubing, or if there are a lot of them, I've welded nuts on a thin strip of flat bar and positioned it inside the tube and secured it with plug welds next to the bolt holes. That works quite well on something that is already finished, as the small plug welds cause less finish burn.