Pressed steel swivel caster, medium heavy duty brackets, with top plate fitting. Wheel with thermoplastic polyurethane tread, with nylon wheel center. Bracket: Made of heavy pressed steel, swivel bracket with double ball bearing in the swivel head, swivel head seals. The special Blickle dynamic riveting process of the swivel head results in minimal swivel head play and smooth rolling characteristics with an increased service life achieved by the work hardening of the ball race grooves. Bolted wheel axle. Zinc-plated, blue-passivated, Cr6-free.