Dual wheel casters offer higher weight capacities with minimal overall heights, better load distribution, floor protection and increased mobility than single wheel casters by spreading the weight over a wider floor area while offing wheel differential action, resulting in less friction between the wheels and the floor, requiring less effort for the caster to swivel. Kingpinless Casters are designed for unsurpassed durability and use in abusive and demanding shockload applications that may cause tradional kingpin casters to fail. The top plate and inner raceway is a unique one piece construction (stronger than machined and welded designs); the inner and outer raeways are made from hot forged (ASTM 1045) steel, are precision machined and hardened and are held together by 1/2? hardened (HRC45) steel ball bearings. The legs are made from 3/8? steel and are uniformly double welded to the outer raceway, for optimum mobility, strength and stability. 3/4? grade 8 axle with lock nut.