The flanged wheels are 3 or 4 inch tread diameter with 1 -3/8 inch minimum rolling face and 4 or 5 inch diameter flange. Wheel tread is to be turned steel with a tread and raceway hardness of Rockwell C-58 minimum. The flange thickness is 7/16 inch at the base and 5/16 inch as the outside diameter. The wheels are double row retainer or full ball complement bearings with an integral outer race/tire, chrome steel balls and alloy steel inner races. The sealed for life bearings utilize two double lip spring loaded seals. Wheels are grease packed at the factory. The bearing inner race is bored to accept a 7/8 or 1 inch diameter axle and has a slot for cotter pinning the inner race to the axle.