Can it be MIG welded or just TIG welded?

4130 can be MIG welded but it is not the preferred process and may not be allowed in competition or certain applications.

http://www.millerwelds.com/powerclick/powerclick_0307.html

Thanks, I was just planning on making some A arms for my banshee, I think the strength issue can be overcome with a few gussets with the ER80 wire. Thanks.

It is common practice in many fab shops to mig chassis and tig suspension.



:)

Back in the day, Oxy-Acetylene was the preferred method.

Eric, you can mig chromoly, but it will get brittle near the welds. You will have to take a torch and heat the tubing around the weld area slowly, backing the temperature down slowly, to stress relieve.