Listing is for a set of four (4) Service Caster Series #30 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 6" diameter by 2" wide semi steel cast iron wheel and maintenance free precision ball wheel bearings capable of supporting a total weight of 4,1,000 lbs. (1,200 lbs./caster). When searching for a reliable and durable solution for heavy duty projects, consider Service Caster’s Series 30 semi steel cast iron wheel casters. The Service Caster Series #30 is ideal for material handling, carts, equipment, and shop projects. The semi-steel cast iron wheel is built to withstand high capacity, heavy loads up to 1250 lbs and in temperatures up to 600°F. An economic choice over steel, semi-steel wheels are abrasion resistant and rugged. Finely crafted with a machined hub, wheel face and double ball bearing heat treated raceways, these versatile casters are ideal for a wide range of applications, such as dollies, platform trucks, warehouse carts and freight terminals. Or ensure a smooth and secure ride for industrial and commercial equipment. Even drywall carts, welding carts, and wall panel carts will be ready to roll on the Series 30, keeping you moving forward. Service Caster is unsurpassed in quality, reliability, and excellent customer service. Count on us to move you forward.