... Stair tread is fabricated by grating, nosing plate and side plate.Main type: 1. Checkered plate nosing , Bolted fixing anti-slip 2 ... bar pitch12.5, 15, 20, 23.85, 25, 30, 30.16, 30.3, 34.3, 35, 40,41,60mm. US standard ... : 1"x3/16", 1 1/4"x3/16", 1 1/2"x3/16", 1"x 1/4", 1 1 ...