Swivel castor, housing made of welded steel, bright zinc plated, blue passivated. Sealed swivel bearing with dual purpose bearing and tapered roller bearing, threaded king pin and locking nut secured, grease nipple.Wheel centre: cast iron, painted. Convex tread R100mm made of
Premium Polyurethane (Ultratech), casted, 83 Shore A thickness 15mm,precision ball bearing, sealed. Suspension with 3 springs for better off-load and heavy duty operation.