Stair Tread Aluminum 6061 Stair Tread 1.25 in Bearing Bar Height 0.188 in Bearing Bar Thickness 2.5 in End Plate Height Top Surface Smooth Nosing Surface Grooved Bearing Bar Spacing 1.188 in Number of Bearing Bars 7 Tread Depth 8 9/16 in Mounting Hole Spacing 4.5 in Includes Mounting Hardware No 7/16 in Mounting Hole Diameter 1 7/16 in Mounting Hole Length 7/16 in Mounting Hole Width Number of Mounting Holes 4 Mounting Hole Center to Tread Top 1 3/4 in