Casters are indispensable components in logistics handling equipment, medical devices, industrial machinery, and office furniture. Based on structural differences, common types can be roughly divided into "shock-absorbing casters" and "swivel casters." The two differ significantly in spring structure, rotation mechanism, load capacity, wheel surface hardness, installation methods, and other dimensions. Confusing them during selection often leads to high pushing resistance, noise, floor damage, or equipment vibration. The following systematically reviews the two types of casters from four perspectives: structural principles, core parameters, typical scenarios, and keyword indexing, to help procurement, design, and maintenance personnel quickly match their needs.

1. Structural Differences: From "Shock Absorption Module" to "Rotation Mechanism"

1. Shock-Absorbing Casters

Keywords: spring shock absorption, elastomer, shock-absorbing bracket, wheel frame swing, buffer gasket, eccentricity, damping coefficient

The core feature is the addition of a shock absorption module between the bracket and the wheel frame. Common solutions include:

- Metal springs: fatigue-resistant, long lifespan, suitable for high-frequency vibration conditions;

- Polyurethane elastomers: maintenance-free, corrosion-resistant, used in clean rooms or humid environments;

- Spring + damping pad combination: balances cushioning and vibration absorption, often used in medical carts and precision instrument handling.

Shock-absorbing brackets are usually designed with a 3°–5° swing angle. When the road surface is uneven, the bracket can slightly swing to absorb shocks and reduce the peak acceleration transmitted to the vehicle body.

2. Swivel Casters

Keywords: turntable, ball bearing, kingpin, double raceway, seal ring, top plate, stem, expansion sleeve, threaded rod, directional lock, full brake, side brake

The structural core is the "rotation mechanism," composed of upper and lower raceways, balls, and kingpin (or rivet), enabling 360° horizontal rotation. High-end series use double raceway precision bearings with long-lasting lubricants, allowing starting torque as low as 0.3 N·m, enabling easy one-handed steering. To suppress "serpentine" swinging during high-speed movement, some models offer "directional lock" or "full brake" functions, which lock the rotation or wheel surface by stepping on a pedal, balancing flexibility and straight-line stability.

2. Functional Focus: Cushioning vs. Steering

1. Shock-Absorbing Casters

- Reduces vibration acceleration by 30%–60%, protecting sensitive goods (glassware, optical equipment, cold chain medicines);

- Reduces noise by 5–10 dB, suitable for quiet environments such as hospitals, libraries, and star-rated hotels;

- Extends the lifespan of vehicle weld points and bolts, lowering maintenance costs.

The trade-off is an increase in structural height by 15–30 mm, and the spring stiffness must match the load: if the load is too light, the spring cannot compress, losing shock absorption; if too heavy, it bottoms out, amplifying impact.

2. Swivel Casters

- Low steering torque, allowing aisle width reduction by 20%, suitable for narrow workshops, elevator cabins, and supermarket aisles;

- Standard installation methods include top plate (common four-corner hole distances 45–76 mm), stem (diameter 20–40 mm), and threaded rod (M8–M16), enabling quick connection with profiles, steel pipes, and sheet metal holes;

- Optional "full brake" pedal locks both the wheel surface and rotation mechanism simultaneously, preventing carts or industrial ovens from rolling away.

The downside is the lack of cushioning structure; if the floor has expansion joints or steel plate overlaps, the vehicle body tends to vibrate periodically, which may cause screws to loosen or weld fatigue over long-term operation.

3. Cross-category: Shock-Absorbing Swivel Casters

With the popularization of wheel surface materials such as polyurethane (PU), thermoplastic rubber (TPR), and nylon-modified elastomers, a "shock absorption + swivel" composite structure has emerged:

- Wheel surface hardness Shore A 65–85, inherently absorbing minor vibrations;

- The bracket still retains the standard rotation mechanism, achieving 360° steering;

- Highly integrated, does not add extra spring brackets, overall height is comparable to ordinary swivel casters.

These products are often labeled as "shock-absorbing swivel casters" or "elastomer swivel casters." Under load conditions of 50–200 kg and speeds ≤4 km/h, they can replace pure spring shock-absorbing wheels, reducing overall costs by 15%–25%.

4. Selection Process: Four Steps

1. Confirm total load and single wheel load

Formula: Single wheel load = (equipment weight + maximum cargo weight) × safety factor 1.25 / number of wheels. If the floor is uneven, the safety factor should be increased to 1.4.

2. Assess floor conditions and speed

- Epoxy floors, PVC floors: prioritize PU or TPR, low noise and floor-friendly;

- Cement expansion joints, steel plate splicing: consider spring shock absorption or elastic wheel surfaces;

- Speed >4 km/h (e.g., electric tow carts) require double raceway bearings, metal wheel surfaces, or high-rebound PU to avoid heat generation and delamination.

3. Determine installation method and hole spacing

Top plate hole spacings of 45×45 mm, 50×50 mm, 58×58 mm, 72×72 mm are European standard series; stem lengths 50–100 mm must match pipe wall thickness; threaded rod specifications must be checked against vehicle steel plate thickness and nut welding space.

4. Functional accessories

- Directional lock: for long-distance straight pushing, reduces swinging;

- Full brake/side brake: prevents rolling on slopes;

- Dust cover: Prevents hair and dust from entering the raceway in the food and pharmaceutical industries;

- Conductive wheel: Resistance ≤10⁴ Ω, used in electronic assembly workshops to prevent static accumulation.

5. Maintenance and Lifespan

- Lubrication: Replenish lithium-based grease every 6 months or 500 km; shorten to 3 months in high dust environments;

- Inspection: Check if wheel surface wear is even; uneven wear indicates bracket deformation or overload;

- Tightening: After the first full load on newly installed wheels, retighten the mounting bolts to prevent loosening due to "settling";

- Replacement: When the wheel surface wears down by 3% in diameter or shows rubber cracking or PU delamination, replace the entire wheel to avoid direct bearing damage.

6. Quick Reference Table of Keywords

Shock-absorbing casters: spring brackets, elastic shock absorption, buffer casters, medical casters, silent casters, vibration isolation wheels, swivel brackets, damping coefficient, vibration attenuation

Swivel casters: rotating casters, mobile casters, top plate casters, stem casters, fully braked swivel wheels, directional locks, double raceways, ball turntables, Kingpin structure

General parameters: load capacity, wheel diameter, wheel width, installation height, turning radius, starting torque, braking method, wheel surface hardness, bearing type, operating temperature, conductive/anti-static, RoHS, REACH

Conclusion

"Shock absorption" and "swivel" are not opposing concepts but structural solutions addressing different pain points. If the working condition is sensitive to vibration, prioritize evaluating spring shock absorption or high-elasticity wheel surfaces; if the passage is narrow and frequent turning is required, choose swivel casters with flexible rotation and braking functions. Clarify the three core variables of load, floor, and speed, then compare bracket structure, wheel surface material, installation size, and functional accessories to precisely select the most suitable caster from thousands of SKUs, balancing cost, lifespan, and user experience.