Listing is for a set of four (4) Service Caster Series #KP30 casters, two (2) swivel casters with bolt on swivel locks and two (2) swivel casters with side lock brakes, with 6" diameter by 2" wide solid polyurethane wheels capable of supporting a total weight of 4,800 lbs. (1,200 lbs./caster). When searching for a reliable and durable solution to your caster needs, consider Service Caster Series KP30 solid polyurethane wheel casters. The Service Caster Series KP30 features a non-marking, non-marring polyurethane wheel. Molded as one solid piece, this wheel is free from debonding, and will not flatspot, as can occur with comparable polyurethane wheels, ensuring a smooth and solid roll over long periods of time. Featuring a Kingpinless hot forged ASTM1045 steel design that increases caster durability and integrity, the series KP30 eliminates problems associated with kingpin failure due to severe shock loading. In addition, the Kingpinless design features 3/8” diameter HRC45 steel ball bearings which absorb thrust and load in severe environments. Lastly, Service Caster’s Series KP30 casters are finely crafted with grease fittings, and 4 position notches to accept 4-position locks. These highly versatile casters are ideal for a wide range of applications, such as dollies, platform trucks, warehouse carts and freight terminals. Even drywall carts, welding carts, and wall panel carts will be ready to roll on the Series KP30, keeping you moving forward.