Iron Core Polyurethane (PU) · Shore 95A · Galvanized 5.5 mm Bracket · No Spring (Rigid) 1. Product Overview The K01 4" (100 mm / 4 inch) is a heavy-duty industrial caster built around an iron-core polyurethane (PU) wheel in Shore 95A. With a load capacity of 350 kg per caster (1400 kg on a standard 4-caster system), it is the lightest and most compact in the K01 range — ideal for equipment where floor space and manoeuvrability matter more than extreme load capacity. The 50 mm