You will notice that the White Industries fixed cogs are unique when compared against traditional fixed gear cogs. There is a problem with threaded fixed gear cogs, they have a tendency to strip 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 hubs - a simple, positive solution.
The cogs are made out of 8620 case hardened steel and have an electroless nickel finish. Available in sizes 13t - 20t in both 3/32" and 1/8" widths. The cog is designed to be used with a standard English 1.29 x 24 tpi threaded lock ring.