Zinc-plated solid steel shaft for attaching and supporting rollers. Shaft length is 1 1/4" longer than roller being mounted. Roller Size Length Shaft Diameter Shafts and Nuts 4" 5 1/4" 1/2" 4" 5 1/4" 5/8" 5" 6 1/4" 1/2" 5" 6 1/4" 5/8" 8" 9 1/4" 5/8" 10" 11 1/8" 5/8" 11"