Common Terms in the Caster Industry

— A foundational guidebook for procurement, sales, and technical professionals

I. Structural Section

1. Wheel

The core components that support and generate rolling motion. Common materials include rubber (ER), polyurethane (PU), nylon (PA), cast iron (CI), stainless steel (SS), and more.

2. Mounting Bracket / Swivel Plate

The load-bearing components connecting the device to the wheels are divided into two types: swivel and rigid.

3. Swivel Bearing

A component that enables the bracket to rotate horizontally by 360° is commonly equipped with ball bearings or plain bearings.

4. Bushing

The friction-reducing component located between the axle and the wheel hub is commonly made from copper alloy or engineering plastic.

5. Brake

It is divided into directional lock and wheel brake, used to lock rotation or rolling.

II. Types Section

1. Swivel caster

It can swivel horizontally, making it suitable for equipment that requires frequent steering.

2. Rigid Caster

Only linear scrolling is provided, suitable for applications requiring stable trajectories.

3. Omni wheel (Omni wheel / Mecanum wheel)

Multi-directional sliding is achieved through diagonal rollers, commonly used in AGVs and robots.

4. Central Control Caster (Kingpin-less Caster)

The central rivet has been removed, and the rotating component is now manufactured through integral forging, offering superior impact resistance and maintenance performance—perfect for heavy-duty or high-frequency usage scenarios.

III. Materials Section

1. Nylon (PA6 / PA66)

Wear-resistant and impact-resistant, suitable for both indoor and outdoor use, offering excellent value for money.

2. Polyurethane (PU)

It features a wide hardness range, low rolling resistance, and minimal noise, making it ideal for protecting floors and suitable for environments where silence is essential.

3. Rubber (NR / SBR / NBR)

It has good elasticity and excellent shock-absorbing performance, but its aging resistance is only average.

4. Cast Iron (CI)

It features high load capacity and excellent temperature resistance, but demands strict ground conditions, making it predominantly used in high-temperature or heavy-load industrial environments.

5. Stainless Steel (SS304 / SS316)

Corrosion-resistant and easy to clean, meeting food-grade and cleanroom requirements.

IV. Performance Parameters Section

1. Load Capacity

The maximum allowable static and dynamic loads for a single wheel must be calculated as the equipment's total weight multiplied by the safety factor (typically 1.25–1.5).

2. Temperature Resistance Range

The material can operate continuously in an ambient temperature range of, for example, –30 °C to +80 °C.

3. Rolling Resistance

The level of horizontal thrust required to initiate and sustain motion depends on tire stiffness, surface roughness, and bearing type.

4. Impact Resistance

The ability of a material to withstand instantaneous impact without developing cracks or undergoing permanent deformation.

V. Installation Methods Section

1. Plate Mounting

A four-hole or five-hole baseplate, secured to the equipment baseplate with bolts; the mounting surface must maintain flatness.

2. Stem Mounting

The threaded rod is inserted into the equipment base and secured with a nut, making it ideal for applications requiring quick assembly and replacement.

3. Expanding Sleeve Installation

Utilizing a conical sleeve that radially expands to secure itself within the tubular footrest, eliminating the need for welding or tapping.

VI. Function Expansion Section

1. Silent Caster

Choosing an elastomer tread and pairing it with precision bearings can reduce operating noise to ≤45 dB.

2. Anti-static Casters

Tread resistance ≤10⁴ Ω, enabling prompt dissipation of static electricity and meeting the requirements for electronic assembly and explosion-proof areas.

3. Corrosion-Resistant Caster

The brackets and fasteners are made of stainless steel or galvanized nickel, and have passed the 720-hour neutral salt spray test.

4. Heavy-duty caster

Single-wheel load capacity ranges from 1 ton to 20 tons, typically featuring a double-row raceway design, forged brackets, and high-strength wheel hubs.

VII. Standards and Certification Section

1. DIN EN 12532 / EN 12533

European caster and wheel standards, covering dimensions, static load, fatigue, and braking test methods.

2. DIN 4102 / EN 13501

Fire resistance rating of flooring materials, used to evaluate the flame-retardant performance of wheel-surface materials.

3. FDA 21 CFR §177 and EU 10/2011

Food-grade material requirements, suitable for food processing and the pharmaceutical industry.

4. RoHS & REACH

Restrict harmful substances and chemical registration requirements to ensure products comply with environmental regulations.

VIII. Geometry and Details

1. Swivel radius

The horizontal distance from the rotation center to the outermost edge determines the minimum turning space required for the equipment.

2. Offset Distance

The horizontal distance between the wheel centerline and the turning centerline affects steering flexibility and stability.

3. Dual-wheel Design

Two wheels share the load in parallel, reducing the ground pressure on each individual wheel while enhancing stability and off-road capability.

Conclusion

Familiarity with and proper use of the above terms can help reduce ambiguity, enhance communication efficiency, and ensure clarity during technical discussions, specification confirmations, and quality inspections. It is recommended to describe requirements in a seven-part format—“Structure-Type-Material-Size-Capacity-Function-Standard”—when making inquiries or drafting technical agreements, ensuring that both suppliers and buyers share a consistent understanding of the product.