... industry and so on.Standard descriptions:1. Bearing bar(load bar):20x3 ..... 75x10 mm.2. Bearing bar pitch: 12.5, 15, 20, 23.85 ... : 1"x3/16", 1 1/4"x3/16", 1 1/2"x3/16", 1"x 1/4", 1 1/4"x ... 1/4", 1 1/2"x 1/4" etc.3. Cross bar pitch: 38,50,76,100,101.6mm4 ...