The thread guards are metal or plastic discs fixed in place between the spanner bushing and caster leg to prevent loose threads from being wound around the axle.
Zinc plating is the standard finish for the caster rigs and other hardware.
Lube-type axles with drilled spanner bushings for relubrication are furnished on all models, because thread guards block access to fittings in the wheel hub. Wheel Bearing Seals, for roller bearing wheels. Main and Secondary Load Bearings hardened and polished steel balls rotate in two heat treated raceways. Lube Fitting - to swivel assembly.