Listing is for a set of four (4) Service Caster Series #KP30 casters, two (2) swivel casters with side lock brakes & bolt on swivel locks and two (2) swivel casters with a bolt on swivel locks, with 4" diameter by 2" wide v-groove cast iron wheels capable of supporting a total weight of 3,200 lbs. (800 lbs./caster). When searching for a reliable and durable solution to your caster needs, consider Service Caster’s Series KP30 semi steel cast iron v-groove wheel casters. The Service Caster Series KP30 v-groove wheel is designed to roll on 45 degree angled track, and also has a flat face suitable for non-tracked use. The semi-steel cast iron wheel is built to withstand high capacity, heavy loads up to 1250lbs and in temperatures up to 600°F. An economic choice over steel, semi-steel wheels are abrasion resistant and rugged. 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.