Looking for elbows and tees for square aluminum tubing

[bigyankfan]

I am trying to make a frame out of square aluminum tubing and I was looking for elbows and tee that i could slip into the ends of the tubing and rivet into place. I tried looking on mcmaster.com but I don't know what they are called and my e-mails to them have gone unanswered. Any ideas or suggestions? Thx.

 

[bigyankfan]

NVM, someone here at work told me about www.eztube.com. That is exactly what I was looking for.