1.Sinosteel-Fortune 500 2.ISO9001:2008 3.ASTM A36 steel grade 4.8 types by welding or bolts 5.FRP/abrasive nosing available 1. Sinosteel Steel Stair Tread TypesT1: Welded fixing, banded ends, no nosingT2: Bolted fixing, holed end plates, no nosingT3: Welded fixing, banded ends, checkered plate nosingT4: Bolted fixing, holed end plates, checkered plate nosing1.5 Welded fixing, banded ends, nonslip ...