... 3~30mm 3.ISO Standard,API certificate astm oil pipe 4 inch SpecificationOD 33mm - 406mm(1”~16”) ... ASTM A106/53 Gr.B, A178-C,A210-A-1,A315-B,AISI1020),45#(AISI1045), 16mn( ... transport, building, machinery, traffic, aviation, oil development etc. seamless pipe for low and medium pressure boiler,high prssure ... 10%,length +/-2 cm 1.Steel wall without oxide layer 2. No cracks wide mouth squash3.To withstand ...