EG:

DOM tubing: http://www.steeltubeinstitute.org/domprocesses.htm is made by Drawing it Over a Mandrel. The process makes a very strong, uniform (OD, ID and wall thickness) tubing with excelent strength and a nice finish.

I actually prefer mild steel tubing because I am more confident with my welding ability on that stock. Since I'm not building race cars, I'm not that worried about a little extra weight.

Dave,

What kind of rod do you use on moly?