... inch WT:3mm to 20mm standard:GB,ASTM,JIS,DIN,API5L,API5CT steel grade:ASTM A106,A53,X42,X52,X60,PSL1 SIZETHICKNESS ... (mm)STEEL GRADESTANDARD1”3-9 ASTM A106,A53,A333; JISG3456,G3454,G3455; ST37,ST42,ST45-8 ... ,ST52; GB 20#,10#,45#,16Mn ASTM, JIS, DIN, GB1 1/4”3-91 1/2”3 ...