... 2.ASTM A123,SS400 3.Common pitch:30mm&40mm 4.Used in flooring,walkway ect. Stair TreadStair Tread DescriptionStair ... -1/2"x3/16",2"x3/16",2"x1/4".3. Stair tread Bearing Bar Pitches:12.5mm,15mm ... 5mm,34.33mm,35.33mm,38mm,40mm,41.25mm,50mm,60mm4. Stair tread Cross Bar Pitches: 38.1mm ... , 50mm, 75mm, and 100mm,101.6mm(4").5. Stair tread Standard Grating Panels Sizes: ...