Can I Mig Weld B7 Threaded Rod?

[coollx]

I have to make a fixture and would like to use 1/2" B7 threaded rod as part of it. I need to join short lengths of right hand and left hand threaded pieces.

Ideally a threaded coupler would be perfect but I can't find one for fine thread so I thought about making one. My plan would be to take a solid piece of square steel about 3" long and drill a hole through the center of it the size of the rod I'm using. Then simply insert each piece of threaded rod 1 1/2" into the square stock and weld the rod in place on both ends of the square stock.

I'm a hobby welder with limited experience at this point and wonder whether
B7 rod, which I know is fairly hard stuff, can be welded with my HH175?

Thank you

[Broccoli1]

Since this is a hobby set up wouldn't be my first choice-Most likely gonna crack on ya.

What is is for?

It is Heat Treated and any welding will certainly change the properties that you wanted in a hardened All- Thread.

Unless you got some way to anneal it and then heat Treat after welding.

Why B7?

[Sberry]

How hard is it? Like a grade 5 low carbon low alloy bolt? If so it will weld well.

[Broccoli1]

From what I can find-- 4140

[coollx]

I think it's hardness is between grade 5 and grade 8.

I'm making an adjusting rod on a fixture for my vertical mill and want to use a heavy enough threaded rod that has 20 threads per inch which is why I picked 1/2" x20. It doesn't have to be high strength but one end of the rod needs to be left hand thread and the other end right hand. B7 is the only stuff I can find that comes 1/2" x 20 in left and right thread.

[Broccoli1]

Weld it up.

[Wyoming]

...or go with your original idea of a coupler. Cross drill the coupler and pin the two threaded sections to the coupler with drift pins. It may even be worthwhile to do the pins so that you can swap out the threaded sections if there is enough usage to cause backlash down the line.

[enlpck]

Welding B7 is not recommended. Very likely to crack.

[usmcpop]

Most references I see say AISI 4140/4142 quenched and tempered.

Can you weld a pair of 1/2" x 20 TPI lug nuts together and use that as a coupler? Obviously you'd need one right hand and one left hand nut.

[Wyoming]

Coollx,
Rereading your thread...do you even need a coupler or would a single threaded rod work with one end Lhand and the other Rhand? If so, PM me with the measurements and I'll see what I can turn up for you. Probably the best grade I can get around these parts would be common cold rolled steel.

[coollx]

Wyoming, a single rod with left hand threads at one end and right hand at the other would work as long as it was 1/2"x20. I could then either epoxy a single nut in the middle or pin one in place to serve as a means to turn the rod for adjusting purposes.

Does anyone make such a rod? Maybe I just missed it when perusing the McMaster-Carr and MSC websites.

Thanks

[coollx]

After I sent my last response I decided to take another look at the McMaster-Carr website and sure enough they carry threaded rod with left and right threads on the opposite ends. The only problem is they only offer 1/2"x13 but it would probably be a easier solution for me. I think I just need to re-engineer my fixture to incorporate this rod. Because of the slack difference between 1/2" x20 and 1/2" x13 thread I'll probably need to use a backup nuts to lock the rod solidly in place after I indicate in the fixture. But it should work.

Thanks for everyone's input.

[usmcpop]

Aww... you got to try the welded lug nuts, just to see how it works out

[delwelds]

have you tried looking at McMaster-Carr for a threaded coupler? they have just about everything you could imagine.

[hogan]

The rod you want is available in A36 and A307, both weldable, both have your thread requirements.