This 6" x 3" polyurethane on cast iron wheel swivel caster with face brake is a durable, high capacity wheel that fits almost any budget. Polyurethane tread is floor protective and non-scuffing.Our 75 Series casters are constructed from high quality heat-treated AISI 1045 laser-cut steel. A precision machined raceway combined with fully welded legs (inside and outside) and kingpinless design delivers superior strength in rugged applications. Kingpinless casters eliminate kingpin failure ? the leading cause of caster failure.