api steel pipe standard: GB/T, ASTM, API size:1-24" api steel pipe1. Standard: GB/T, ASTM, API, DIN etc2. Material: A106/A53 GRB, 5L GRB, ST37 ST42 ST52 ETC3. OD: 1/2-244. WT: SCH10-SCH1605. Usage: construation, water transport, gas and oil transfer etc6. Length: 5.8 or 6M or 12M or random length requried by customers7. Surface: black or oil painting as rusty protect8. Ends: required by customer, ...