This 12 slot trailer spindle castle nut measures 1" - 14, sized to fit standard 1 inch spindles on a wide range of trailer axles. This 12 slot style of castle nut is used on standard axles that use a cotter key to secure the castle nut in place. The 12 slot design is useful for offset drilled cotter key holes that might not accept a cotter key through a standard 6 slot castle nut. This castle nut is compatible with our range of Black Painted Straight and Drop Trailer Axles. This nut is used with a flat washer to engage your hub's bearings and keep the hub assembly secured on your axle's spindle. If you are having trouble with getting your cotter key through your current spindle setup, this castle nut might be a way to solve your problem!Features- 12 Slot Trailer Castle Nut for 1 inch Spindle- 1-inch by 14 thread- 1 1/2 inch outer diameter- 12 Slots provide more paths for cotter key insertion