O.D: 2-3/8" to 24" W.T: 3.2mm-12.7mm Standard: API 5L, API 5CT, ASTM A53, ASTM A500, GB9711.1/2 Place of Origin: Tianjin, CN Black steel pipe is made of hot rolled or cold rolled coil and strip,which is widely used in the fields of construction,low-pressure liquid transportation etc...Thickness:3.2mm-12.7mmstandards:ASTM, API, JIS, DIN, EN, BS, GB Electric Resistance Arc Welded (ERW) Steel Pipe