astm oil pipe 4 inch 1.OD 33mm - 406mm(1aa~16aa) 2.WT: 3~30mm 3.ISO Standard,API certificate astm oil pipe 4 inch SpecificationOD 33mm - 406mm(1”~16”) with thickness of 3~30mmStandardGB/T8162,GB/T8163 and DIN/JIS/ASTM standarda. DIN Standard 10#(ST37-2,ST35-8),20#(ST42,ST45-4/8),45#(DIN CK45),16mn(ST52.4) etc.b. JIS Standard10#(STPG38,STS38,STB30,STB33,Stb35), 20#(STPG42,STB42,STS42,JIS S20C),45 ...