You will notice that White Industries' fixed cogs are unique when compared against traditional fixed gear cogs. There is an industry-wide problem with all threaded fixed gear cogs - they tending to strip their threads. To avoid this problem White Industries designed their fixed gear cogs with a spline interface. The spline interface mates to their single speed hubs on both track and ENO - a simple, positive solution. The cogs are made out of 8620 case hardened steel, and are available in sizes 13t - 20t. The cog is designed to be used with a standard English 1.29 x 24 tpi threaded lock ring.