mild steel hollow pipe 1) Standard:API 5L,ASTM 36.10M,A106,A53,DIN ... ) Surface treatment:bare,black painting,anti rust oil,hot dipped galvanized,3pe,etc8) Length: 5.8 meters for 20' container, 6 ... ,chemical,power,shipbuilding,boiler,construction,,metallurgy,etc mild steel hollow pipe