... grade of Steel Pipe: grade B , 20# , Q235 , ST 52 , ST374) Standards of Steel Pipe: ASTM A106 , ASTM 53 , API 5L and etc. ... 5) Surface of Steel Pipe oiled or black painted to ... DIN17120,API 5L, API 5CT, ASTM A106, ASTM A53,ASTM A179,ASTM A210,ASTM A36,JISG3454,JISG3455,JISG3556,GOST8732,GOST8731MaterialGr. B, Gr. C; X42,X46,X52, ...