K01 Series — 6" (150 mm / 6 inch) Heavy Duty Caster Iron Core Polyurethane (PU) · Shore 95A · Galvanized 5.5 mm Bracket · No Spring (Rigid) 1. Product Overview The K01 6" (150 mm / 6 inch) is a heavy-duty industrial caster built around an iron-core polyurethane (PU) wheel in Shore 95A. With a load capacity of 450 kg per caster (1800 kg on a standard 4-caster system), it is the the medium-heavy workhorse — the go-to size for mould shops, foundries and transformer handling