... plain steel grating, serrated steel grating, I section type steel grating. We are the leading manufacturer and ... mm):The specification of plain type and serrated type bearing bar is 20 x 3 to 100 x 6; the ... 7 x 4, etc. 2) Bearing Bar Pitch (center to center): 15, 30, 40, 60, 80, 90mm etc ... galvanizedP PaintedU Untreated 7) Steel grating standards: A) China: YB/T4001-1998 B) USA: ANSI/NAAMM (MBG531-88) C ...