Pressed steel swivel caster, closed medium heavy duty brackets, top plate fitting and 'stop-fix' brake. Heavy duty wheel with Blickle Extrathane®. polyurethane tread, with aluminum wheel center. Bracket: Made of heavy pressed steel, with four-point contact ball bearing in the swivel head for optimal absorption of vertical and horizontal forces, closed sealed swivel head. The use of hardened bearing seats in conjunction with the special Blickle dynamic riveting process provides increased protection against shocks and impact loads and results in smooth rolling characteristics, low abrasion and an increased service life. Bolted wheel axle. Zinc-plated, blue-passivated, Cr6-free.