RWM Casters UIR-0620-08 6" Diameter X 2" Width Urethane on Iron Wheel with Straight Roller Bearing, 1230 lbs Capacity 1/2" Axle diameter, 2-7/16" hub length, 1230lbs capacity^Urethane on Iron wheels with straight roller bearing^92 Shore A durometer hardness^Temperature range from -40 degree F to 180 degree F^Urethane thickness is 1/2"