Curious as to what the grades of steel are from worse to better - relative to those used in frame building. I assume that it starts at high tensile and then moves to 4130, but where does it go from there? Thanks.

From there it goes to the name brand tubing => the big ones are columbus, reynolds, tange, kensei, true temper and dedaccai who each have their own hierarchies from there on; there's a bunch in these hierarchies and they're a quick google search away.

Thanks for the info, Leuky.