Thank you both. From your comments, my conclusion is that seam-welded steel is of a material that doesn't improve from heat treatment, so I can assume that, if properly welded (as guaranteed by NDT), it is the same strength as seamless of the same type. Weaker, non-heat-treatable steels are...
I am trying to figure out the strength difference between seamless tubing, drawn-over-mandrel tubing, and welded tubing. I know seamless is strongest and welded is weakest, but I don't know if this is a 10% difference, 2x, or 10x.
Just to give context, I'm building bicycle parts. Right now...
