... G3457,JIS G3461MaterialQ235, 20#, Q345A53B, A106B, API 5L B,X42,X46,X52,X60, X65ST37.0,ST35.8 ... ,STB42,STS42,STPT49,STS49ApplicationLow and middle pressure fluid pipeline, boiler, petroleum and natural gas industry, drilling ... chemical industry, electric industry, shipbuilding, fertilizer equipment and pipeline, structure, petrochemical, pharmaceutical industrySurfaceBlack painting, varnish paint, ...