Material: heat treated 4140 crmo Axle: 3/8", 14mm Diameter (inch, mm): 1.4", 35mm Length (inch, mm): 4.13", 105mm Extra info: sold as single, smaller diameter, double-butted dent prevention design, light weight design 5 bore holes, between 5 slick cut-outs, slightly longer length to help spining in and out of grinds