Steel Grating Standards: CHINA YB T4001-1998 U.S.A ANSI NAAMM(MBG531-88) U.K. BS4592 1987 NOTES:1 Bearing bar pitches may be 15 to 22, 25, 30, 32.5, 34, 40,50,60,80,90mm,of which 25,30,34 and 40mm are recommended.2 Cross bar pitches maybe 24-200mm,of which 50mm,76mm and 100mm are recommended.3 Steel grating is made by the world first-class equipment, which can arrange the bearing bar and cross ...