Pressed steel swivel caster, heavy duty casters, with top plate fitting and 'stop-top' brake. Wheel with thermoplastic polyurethane tread, with heavy nylon wheel center. Bracket: Made of heavy pressed steel, with heavy fork and top plate, very strong bolted and secured central kingpin, double ball bearing in the swivel head, additionally reinforced by the integration of four specially shaped and hardened bearing seats resulting in a very high resistance to shock and impact loads. Bolted wheel axle. Bolted wheel axle. Zinc-plated, blue-passivated, Cr6-free.