View Full Version : welding 6061-T6 AL

09-30-2002, 05:21 PM
I am making clamps out of 6061-T6 AL.the material is 2.5"x1/4" AL plate welded to 1.5" round x 2.5" long with a 3/4" hole in the center.They are like a gate hinge
These are to be welded and then to be tested.They must be able to hold 15,000lbs.(straight down pull)
What procedure and what type of rod or wire will give the best results.


09-30-2002, 05:46 PM
I've been told that AC TIG is best for Al. Although, I know a really good oxy/acetylene welder can do just as well. I think this is a case where the Welder (the person) is more important than the welder (the process).

Paul H
09-30-2002, 07:12 PM
Just be aware that the process of welding 6061-T6 will anneal the material, and in the non heat treated state, 6061 is about 1/5 the strenght, 12kpsi vs 60 kpsi as I recall.

I would recomend AC tig as well. I know that it can be MIG'd, but the weld is hideous looking.

09-30-2002, 09:39 PM
Paul is correct - you may find it very difficult to find anyone to solution heat treat it except in aerospace country. You could look for someone at

www.thomasregister.com (http://www.thomasregister.com)

Note that there are 3 different search engines 1 US products/materials/some services, 1 services, and 1 World wide services/products.

TIG weld it, or have an aviation welder gas weld it for you. The key here is over build to compensate for lost strength or use a material better suited such as Titanium (stronger than steel but very springy in comparison - very light).

09-30-2002, 11:23 PM
Yukes, I didn't realize that 6061 aluminum would be weakened so much by welding. Thanks for the warning.


10-01-2002, 07:12 PM

Use 4043 weld filler, easisest to work with. TIG is more precise (and for small welds <1 ft probably the best)but MIG will work if you make sure you test out your welds.

The strenght of the metal reduced by heat is localized. It also depends on how much heat is imparted into the weld area. I found some data for 6061-t6 welded w/ a 5356 filler alloy (harder to weld than 4043). The metal was reduced from 35 kpsi to 19 kpsi.