Originally Posted by KILLER"B"
yes HREW and schedule 40 are made from the same 1010 material.
Not necessarily. There are many types of Sch 40, just like there are many types of hot rolled and cold rolled. I know I have 1018 HREW square and rectangle in the garage.
Thats nothing but carbon content. I was referring to the ASTM material spec, in the case of the tube I use, its ASTM A500, grade B. Grade C is stronger, but not not common, and doesn't bend well. A500 B and C are considered structural tubing. A53b is also decent for structures, but butt welded Sch40 for home depot would be crap.