E355 Cold Drawn Over Mandrel Seamless Steel Tubing

E215 E235 E355 Cold Drawn Over Mandrel Seamless Steel Tubing Drawn Over Mandrel Tubing Steel Grade/Steel Material: E155 E195 E235 E275 E355 Delivery Condition: 1 BK Cold finished(hard) 2 BKW Cold finished(soft) 3 BKS Cold finished and stress-relieved 4 GBK Annealed 5 NBK Normalized Cold Drawn Seamless Steel Tubing Size Range: O.D.:6-350mm W.T.:1-35mm L:max12000mm Characteristic: Good concentricity Good OD and ID tolerance High precision Stable quality Smooth roughness E215 E235 E355 DOM Steel Tube DOM Steel Tube Production Process: Raw material → Incoming inspection → Cutting → Heating → Piercing → Hammering →Pickling → Cold-drawing →  Heat treatment → Physical chemistry test → Straightening → Ends cutting → Final inspection → Bundling →Storage