Steel 1020-Drawn Over Mandrel Round Tube 4" OD x 0.12" wall Price

About 1020|Nearly identical to 1018 in practice. The carbon spec ranges actually overlap (1018 is 0.15-0.20%, 1020 is 0.17-0.23%), so depending on the heat you might not be able to tell them apart. 1018 has slightly higher manganese which offsets the lower carbon, making their mechanical properties essentially the same in cold drawn form. The real difference is availability and form. 1018 dominates in bar stock for machining. 1020 shows up more often in DOM tubing and turned/polished bar. If a drawing calls for 1020 and you can only get 1018, it's almost always a safe substitution for non-critical applications. Machines the same as 1018 with the same gummy chip behavior. Both weld easily. Compare to 1018 (more available in machining stock) and 1026 (slightly stronger, the usual tubing grade).

About Round Tube|Hollow cylindrical stock for sleeves, bushings, spacers, and hydraulic cylinders. DOM (drawn over mandrel) tubing machines well and holds tight tolerances. Welded-seam structural tube is for cutting and welding, not precision work.