DOM: Drawn Over Mandrel
ERW: Electrical Resistance Welded
The DOM product is typically concidered a round mechnical tubing (cold Drawn) and has more precision size tolerance and ID to OD concentricity control than the ERW product.
There will probably be a very slight weld flash on the ERW product, the DOM should not have any flash or weld seam visable. There will be move ovality tolerance with the ERW over the DOM. Since you are looking at a scrap yard...I'd go there, bring a caliper, check for roundness and visual straightness, then decide. Typically, I'd go with the DOM product if the cost is not any factor.
Regarding your welding application: These are all low carbon, (DOM may be 1026) with no difference between the two.
Post some pictures when you are done!!
Hi,
ERW is electric resistance welded, and DOM is drawn over mandrel. If your electric resistance welded pipe conforms to ASTM A-53 Type E Grade B, it has a minimum yield stress of 35 ksi and a minimum tensile yield of 60 ksi. DOM is a term applied to electric resistance welding tubing that has been finished by cold drawing through a die & over a mandrel. If your DOM round tubing conforms to ASTM A513 Type 5 or 6, it has a minimum yield stress of 75 ksi and a minimum tensile stress of 85 ksi. DOM will have a better finish, as indicated by Bill.
Hey i really apprecaite the knowledge you pass along I am just 18 and going to school to be a welding engineer and i have a couple weeks before my ceritfaction on mig and arc overhead and vertical. I am very excited. So basically go with the OD pipe..... i want to do it right you know price isn't a concern and the gap for the pipe should be? should there be one if i mill the joints? like in school we use like 1/8" gap and land for pipe in arc welding and mig i know its a totally different application but here again i want to do it right and i know i want to get good penetration and what not, i have a hobart handler 140 i believe its 115v and it runs off 220....my question is i have flux core in right now and i believe i am running .030 diameter flux core wire in my machine right now....what setting should i run this at to achieve proper penetration and should i go with gas instead of the fluzx core and what kind of wire and diameter should i use?
I will for sure u have no idea how much help and stress u take out of it i made pre runner bars for my 1997 s10 zr2 and i took 9th in the stae competion for the Mites competion in michigan