... produce three kinds of steel gratings, they are Plain Style Steel Grating, Serrated Style Steel Grating and ... ) Specifications (mm):The specification of plain type and serrated type bearing bar is 20 x 3 to 100 ... , 75 x 7 x 4, etc. 2) Bearing Bar Pitch (center to center):12.5, 15, ... Untreated, Painting or Hot dip Galvanizing Pitch of Bearing barCross-bar PitchSpecification of steel graing(width×thickness) ...