A typical heavy-duty swivel caster is mainly composed of a top plate, swivel structure, bracket, wheel, axle bolt, nut, and bearing. The cooperation between these parts directly affects the caster’s load capacity, swivel smoothness, and service life.

Top Plate
The top plate is the mounting part that connects the caster to the equipment, usually fixed to the bottom of the equipment with screws. For heavy-duty equipment, the thickness, hole spacing, and steel strength of the top plate are very important. If the top plate is not strong enough, it may deform, loosen, or become unstable after long-term loading.

Swivel Structure
The swivel structure is the key part that allows the caster to rotate 360 degrees. Our heavy-duty swivel caster uses a steel bowl raceway structure, usually consisting of an upper plate, lower plate, steel bowl, steel balls, and a central rivet. The steel balls roll between the upper and lower raceways, allowing the caster to swivel smoothly even under load.

Bracket
The bracket, also called the fork, connects the swivel structure and the wheel. Heavy-duty caster brackets usually use thicker steel plates to improve load capacity and impact resistance. The bracket thickness, forming process, and surface treatment all affect the overall service life of the caster. For humid or corrosive environments, stainless steel brackets or special surface treatments can also be selected.

Wheel
The wheel is the part that directly contacts the floor. Its material affects wear resistance, rolling resistance, noise level, and floor protection. Nylon wheels have good load capacity and low rolling resistance. PU wheels are wear-resistant, shock-absorbing, and more floor-friendly. Rubber wheels are softer and quieter, but their wear resistance and chemical resistance are usually not as good as PU. The final selection should be based on load capacity, floor condition, and working environment.

Axle Bolt and Nut
The axle bolt and nut are used to fix the wheel and are important load-bearing parts of the caster. Heavy-duty casters usually require higher-strength axle bolts to prevent bending, loosening, or breaking after long-term use. The axle size also needs to match the wheel hub and bearing structure, so it cannot be changed randomly.

Bearing
The bearing affects the rolling smoothness and service life of the wheel. According to different working conditions, standard bearings, stainless steel bearings, needle roller bearings, and other types can be selected. If the environment includes moisture, cleaning liquid, or certain chemical corrosion risks, stainless steel bearings can be considered to improve rust resistance and stability.

Overall, heavy-duty casters should not be judged only by wheel size or single-wheel load capacity. The top plate strength, bracket thickness, swivel structure, wheel material, and bearing configuration should all be considered. Only when these structures match the actual working conditions can the caster remain stable, smooth, and durable under high load, frequent movement, and complex floor conditions.