... bar pitches may be 12.5, 15 to 30, 40, 60, 80 and 90mm; of which 30and 40mm are recommended2) ... Cross bar pitch may be 30, 38, 50, 76 and 100mm; of which 50 and 100mm arerecommended3) Advantages of steel grid planks ... , 30.3, 32.5, 34.3, 35, 38.1, 40, 41.25, 60, 80mm etcUS standard: 19-w-4, 15-w ... -2, 15-w-2 etc. 3Twisted Cross Bar Pitch38.1, 50, 60, 76, 80, 100, 101.6, 120mm, 2'' & 4'' etc ...