Round Steel Mechanical Tube, is a welded mechanical round steel tube with the internal welded seam removed creating a smooth internal surface. Tubes with wall thickness of 1/2 or less are DOM (drawn over a mandrel) to produce a tube having more exact dimensional accuracy and tolerances, and a very smooth inside and outside finish. DOM round steel tube is ideal for more stressful applications requiring higher quality, increased mechanical properties, uniformity, strength, and soundness. Larger diameter and wall thicknesses of over 1/2 inch are generally Cold Drawn Seamless. Tubes with 10 ga. (.135) and lighter are made from 1020 steel, heavier wall tubes are made from 1026 steel.