I can't even imagine the threads failing. What kind of weight were you using, and what material did you use for your T bar? Was the flange tightened down all the way on the pipe threads? If you could post pictures of the damage that would be helpful.
Since I built my T bar I've done many thousands of swings with anywhere from 50 to 75 pounds, and I've done low-rep swings as heavy as 140 pounds, and never had any problem with my equipment. I'm sure there's an upper limit on the weight it will hold without failing, but I seriously doubt that my strength level will ever threaten that limit.
As for next time, I suppose you could use epoxy to secure it in place if you want. Welding it really seems like overkill unless you're using a crazy amount of weight. At the end of the day though, do whatever it takes to give you confidence in the equipment you're using. Good luck with it and keep swinging!
pathfighter wrote:Keep at it. People may not listen to regular madmen, but they do listen to jacked madmen.