... cover, well cover, stair treads, fence etc. 1) Bearing Bar (Load Bar) Specifications (mm): 20 x 3 to 100 x 6 ... , 75 x 7 x 4, etc. 2) Bearing Bar Pitch (center to center): 12.5, 15, 30, 40, 60mm etc, also be ... and 30, 40, 60mm are recommended. 3) Cross Bar Pitch (center to center): 38, 50, 76, 100mm etc, also be according to ...