Tubbing difference between RHS and ERW

[nutz4sand]

If the designs good/right and its built well I have seen a lot with ERW that are running around fine.

DOM is supposed to be a bit more processed to make it a little more consistant in size and this is supposed to help the strength.

[dunerocket]

DOM starts out as ERW. The additional cold working steps to produce DOM add strength and allow for tighter dimensional controls.

This is a pretty decent look at the process flow

ERW - DOM Tubing Process | Salem Steel North America, llc

[LiveWire]

DOM is also made from 1018 or 1020 as opposed to 1010.

[dunerocket]

DOM is offered in a wide variety of materials, including aluminum. DOM is a process, not a material.

[LiveWire]

That is true, but in the context of this thread, we are talking about steel.