. A05 Series — 6 inch (150 mm) Heavy Duty Aluminium Core Rubber Caster Black · 50 mm Tread · Shore A 70 · Galvanized 5.5 mm Bracket · 6203 Bearing Product Overview The 6 inch (150 mm) A05 heavy-duty aluminium core rubber caster is rated for up to 300 kg per caster — a combined 1200 kg system load in a standard four-caster setup. With a 50 mm tread, Shore A 70 rubber, a 5.5 mm thick galvanized steel bracket and 6203 sealed bearing, it is engineered for smooth, quiet, floor