... (A36)ASTM(A123)BritainBS4592-1995BS4360(43A )BS729AustraliaAS1657-1992AS3679AS1650 2.Bearing Bar Sizes: 1"x1/8",1-1/4"x1/ ... x3/16",2"x3/16",2"x1/4". 3.Bearing Bar Pitches:12.5mm,15mm,24mm,25mm,30mm,30.16mm ... There are three kinds of steel gratings distinguished by different bearing bar types.The respective of features are as follows: ♥ ... and negotiation with old and new customers! Stair Tread Manufacturer