Welding threaded rod to SS plate

[madala]

I am needing to weld several 1/2” threaded rod pieces(6” long) to 3/16” (3x6”) plates. All stainless using TIG.

I tapped the plates and threaded the rod 2/3 of the way leaving a gap at the back to fill with weld. This was easy to weld and seems very strong.

My question: is that sufficient or do I also need to do a fillet weld around the rod on the front side?

I find the fillet a much harder weld to perform and am concerned I’m putting to much heat into the material.

The bracket only needs to support about 50 lb of sheer load

Thanks in advance


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[astroracer]

The threads would have probably been sufficient. You will have no worries with the welds only on the back side.
Mark

 

[MoonRise]

?

You tapped some 3/16" thick stainless plate to 1/2-13 UNC.

Which means you have about 2.4 threads in the plate, not accounting for any chamfer on the holes.

And you then screwed the threaded rod in about 2/3 of the way into that 2.4 threads. So you have that threaded rod actually engaged with approximately a single thread.

And your "50 lb of shear load"? Is that actual shear through the bolt diameter, or shear through the thread (axial load)?

And you did a plug weld inside the back of the threaded hole to try and weld the **** end of the threaded rod to the ID of the threaded hole in the plate?

Just what does this bracket have to do?

 

[PoorOwner]

if it is 1/2" bolt/rod it should engage the material about 1/2"

 

[welder4956]

So, even if the hole had no threads and the stud is inserted 2/3 into a 3/16" plate (1/8" insertion) there is weld metal 1/16" thick holding the rod to the plate. Theoretical load capacity is 70,000 psi tensile strength of weld x (pi x 1/2" rod diameter x 1/16" weld height) = 6,872 lb. It will hold 50 lbs. easy even with no thread engagement.

 

[madala]

Thx for the responses. These rod/plate brackets are to support sun shades over the windows on my new house. The shades weigh about 40 lb and will be supported by 4 of these brackets. I guessed at a load of 40 lb per bracket to account for wind load. The bracket screws to sistered studs with 4 5/16 screws the threaded rod will protrude through rock board insulation and metal siding about 4.5” and then attach to the sunshade. I screwed one up in my shop after pocket welding the back and did some pull-ups on it and it supported my weight no problem. The first few I welded the back and also filet welded the front, but got concerned about the amount of heat I was putting into the stainless and wondered if I was weakening it; hence my question. My reason for tapping the hole was really just to support the rod for welding.


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[BD1]

Plug welding will work. You could tack the front on the 6'' length. Welding all round will pull it slightly and roll up.