... ):The specification of plain type and serrated type bearing bar is 20 x 3 to 100 x 6; the specification of I ... x 5 x 3, 32 x 5 x 3, 38 x 5 x 3, 40 x 5 x 3, 50 x 5 x 3, 50 x 7 ... , 60mm are recommended, America standard is available. 3) Cross Bar Pitch (center to center): 30, 38, 50, 76, 100mm etc, or according to ...