USA-Made Casters:Our solid polyurethane stainless steel casters are made in the USA. American-made casters stand up to the test of time. They’re built tough, meant to handle heavy loads and constant use without breaking down. This means less time worrying about replacements and more time focusing on work that matters. Stainless Steel Casters:CWfutureparts casters use American industrial standard stainless steel brackets, which are corrosion-resistant, high and low temperature-resistant and rust-proof, and can still work normally even in harsh conditions. Solid Polyurethane Casters：The 5 inch industrial caster is made of thickened high-quality polyurethane one-piece die-casting. Compared with other polyurethane casters, this type of caster has stronger load capacity and durability.Casters Diameter: 5", Width: 2", Top Plate: 4x 4-1/2, Overall Height: 6-1/2. These industrial casters are engineered, Heavy Duty Caster Set of 4 to support loads up to 4000 lbs. Delrin Bearings and Bushings：Delrin, a Special engineered plastic, is extremely durable under a wide range of temperature and humidity conditions, as well as is corrosion resistant. Wheels with the Delrin bearings are well suited for applications where brine conditions, steam cleaning, or where excessive water or liquids are present. Wide Application：Heavy duty casters are widely used in clean rooms, laboratories, medical and hospital facilities, animal cages, pharmaceutical plants, autoclaves, food processing, bakeries, dairy, food service, catering, hotels, chemical plants, marine environments, fisheries, Cruise ships etc.