... Thickness: 1 - 80mm 3) Manufacturing standards: GB Boiler Hot Forged round steel pipesFeatures:1) Outside diameter: 20 - 1,067mm 2) Thickness: 1 ... - 80mm3) Manufacturing standards: GB, DIN, JIS, ASTM4) Bevel or varnish to be confirmed5) For the manufacture of low, medium ... or high pressure boilers, water cooling panels, coal-saving devices, ...