3/4″ Castellated or Castle Nut – How to tighten correctly
The purpose of the castellations is to lock the split pin into a castellation to prevent it from dislodging.
3/4″ castle nuts are a UNF fine thread.
Bend half of the split pin forward across the end of the axle. The other half or shorter half should be bend back towards the bearing.
Ensure when bending 1/2 pins back towards the bearing, the pin is flat on the axle nut and not sticking into the bearing itself.
Axle split pins are an essential part of the axle assembly. Without the humble split pin, the entire hub assembly and wheel will detach from your trailer or caravan.