... and stable quality. Product Name Seamless Steel Tubes for Boiler, Pressure Vessel & Heat Exchanger American Standard ASTM A53,ASTM A106,ASTM A333 ... A556, ASTM A179,ASTM A192,ASTM A210 Grade Gr.A,B GRA,B, C; GR1,GR6; GR.A-1,GR.C ... 37.0,St 44.0,St 52.0,St35.8,St45.8,17Mn4,15Mo3,13CrMo44 British standard BS 3059-1,BS ... -2 Grade P235TR1, P235GH, P265GH etc. Size OD1/8"-6"or 8-168.3mm WT 1-18 mm Length 0-12m