Wheel Materials Compared: Polyurethane, Rubber, Nylon, Phenolic, Steel
Five wheel materials dominate industrial casters: polyurethane, rubber, nylon, phenolic, and steel. Each has a load rating, a temperature band, a floor-protection profile, and a chemical resistance it owns. This guide compares all five on the specs that actually matter procurement-side: rolling resistance, temperature band, load capacity, floor protection, cost, and service life. Use it as a filter before picking a caster, not after.
In this guide
Quick Summary Matrix
All five materials on the specs that matter. Use this as the first-filter comparison.
| Material | Load per wheel (typical 5") | Temperature Band | Rolling Resistance | Floor Protection | Cost Index |
|---|---|---|---|---|---|
| Polyurethane | 500-1,500 lb | -20°F to 180°F | Low-medium | Excellent | 1.0x |
| Rubber (solid) | 200-500 lb | -20°F to 160°F | Medium-high | Excellent | 0.8x |
| Nylon (glass-filled) | 800-2,500 lb | -40°F to 200°F | Low | Poor | 0.9x |
| Phenolic | 500-1,000 lb | -20°F to 325°F | Low | Fair | 1.1x |
| Cast iron | 1,000-3,000 lb | -40°F to 500°F | Very low | Very poor | 0.7x |
| Forged steel | 2,000-10,000+ lb | -40°F to 800°F | Very low | Very poor | 2.5-3.5x |
Polyurethane
Polyurethane is the industrial default for 32°F to 180°F service on finished floors. Excellent balance across load, rolling, and floor protection.
- Load band: 500-1,500 lb per wheel at 5" diameter; up to 4,000+ lb at 8" diameter.
- Durometer options: 75A (soft, absorbs shock) to 95A+ (hard, low rolling).
- Strengths: quiet, non-marking, excellent floor protection, best abrasion resistance of polymers.
- Weaknesses: degrades past 180°F continuous, shatters below -20°F, attacked by strong acids and ketones.
- Typical use: manual carts, tugger-towed, general industrial, finished-floor warehouses.
Rubber (Solid, Pneumatic, TPR)
Rubber handles shock and rough surfaces better than any other option. Three sub-types dominate.
- Solid rubber: vulcanized-bonded tread on metal hub; low load (200-500 lb), excellent shock absorption.
- Pneumatic: air-filled tire on wheel rim; outdoor/rough-surface use; load 150-350 lb, punctures possible.
- TPR (thermoplastic rubber): injection-molded hybrid; quieter and cleaner than natural rubber, lower load.
- Strengths: excellent shock absorption, quiet, non-marking, good chemical resistance to most industrial fluids.
- Weaknesses: higher rolling resistance, lower load capacity, attacked by ozone and some oils.
- Typical use: medical, hospital, rough outdoor surfaces, shock-sensitive equipment.
Nylon (Glass-Filled)
Glass-filled nylon is the highest-load polymer and the first choice for freezer/cryogenic service.
- Load band: 800-2,500 lb per wheel at 5" diameter; held at both temperature extremes.
- Glass fill: typically 33% glass fiber; retains impact strength at -65°F.
- Strengths: high load, wide temperature band, chemical resistance, low rolling resistance.
- Weaknesses: marks and damages finished floors, poor floor protection, noisy, no shock absorption.
- Typical use: freezer/cryogenic racks, chemical processing, industrial-grade racks on concrete.
Phenolic
Phenolic is the polymer that holds temperature past 180°F. Laminated canvas impregnated with phenolic resin; rated to 325°F continuous.
- Load band: 500-1,000 lb per wheel at 5" diameter.
- Temperature: -20°F to 325°F continuous; 400°F transient.
- Strengths: high temperature tolerance, low rolling resistance, chemical resistance to most industrial fluids.
- Weaknesses: impact-brittle (chips on pallet-edge impact), no shock absorption, fair floor protection only.
- Typical use: proof boxes, steam-washdown racks, drying ovens, hot production lines.
Steel (Cast, Forged, Ductile Iron)
Steel is the choice when load, temperature, or chemical resistance exceed polymer limits. Three sub-types cover different duty.
| Steel Type | Load (5" wheel) | Temperature | Impact Toughness | Cost |
|---|---|---|---|---|
| Cast iron | 1,000-3,000 lb | -40°F to 500°F | Brittle | Baseline |
| Ductile iron | 1,500-5,000 lb | -40°F to 600°F | Tough | +30-50% |
| Forged steel | 2,000-10,000+ lb | -40°F to 800°F | Excellent | +150-250% |
- Strengths: highest load, highest temperature, chemical-immune, zero deformation under shock.
- Weaknesses: damages finished floors, noisy, no shock absorption, higher cost (especially forged).
- Typical use: foundry, heat-treat, heavy-tooling, aerospace, steel-mill, anywhere loads exceed polymer limits.
Floor Protection Ranking
Ranked from best to worst floor protection, on finished concrete and epoxy:
- 1. Soft urethane (75A-85A): conforms to floor; best floor protection available.
- 2. Solid rubber: excellent non-marking; tiny compression marks under shock.
- 3. TPR: clean non-marking; slightly less conforming than natural rubber.
- 4. Medium urethane (85A-95A): very good; industry standard for most warehouses.
- 5. Phenolic: fair; rigid but doesn't score concrete under rolling load.
- 6. Nylon: poor; point-load marks on epoxy, scores painted-concrete lane markings.
- 7. Cast iron / forged steel: very poor; rolls smooth on concrete but damages epoxy and polished finishes.
Key takeaways
- Polyurethane is the industrial default: 32°F-180°F, finished floors, 500-1,500 lb per 5" wheel.
- Rubber handles shock and rough surfaces; lower load but best shock absorption.
- Glass-filled nylon owns the freezer/cryogenic band and high-load polymer duty.
- Phenolic is the polymer for temperature past 180°F up to 325°F continuous.
- Steel is the only choice past polymer limits; spec forged for impact, cast for static, ductile iron for the middle.
Frequently asked questions
Which wheel material is the industrial default?
Polyurethane 85A-95A durometer on aluminum or cast-iron hub. Covers 32°F to 180°F service, load up to 1,500 lb per 5" wheel, excellent floor protection on finished concrete, low rolling resistance, non-marking. Fits most general-industrial and warehouse applications without spec compromise.
When should I use phenolic over urethane?
When continuous temperature exceeds 180°F. Urethane softens past 180°F and chunks past 200°F. Phenolic holds to 325°F continuous and 400°F transient. Phenolic is also rigid (no shock absorption); if the rack sees pallet-edge drops at temperature, consider high-temp urethane (250°F continuous) or forged steel instead.
Does glass-filled nylon damage floors?
Yes on finished floors. Glass-filled nylon is rigid and has no compression layer; it point-loads the floor and marks epoxy or polished concrete within weeks. Use nylon only on unfinished concrete, industrial-grade floors, or in environments where the rack doesn't cross finished areas. Freezer rooms are typically bare concrete and acceptable.
Is forged steel worth the cost over cast iron?
For impact-loaded or shock-loaded applications, yes. Cast iron is impact-brittle and chips on pallet-edge drops. Forged steel has 3-5x the impact toughness at same temperature rating. For static loads (machine bases) cast iron is fine. Rolling under any impact, spec forged.
Which material has the lowest rolling resistance?
Hard steel on smooth concrete, followed by phenolic, then 95A urethane. Rolling resistance scales inversely with wheel hardness on smooth floors. Soft (75A-85A) urethane and natural rubber have ~30-45% higher rolling resistance than 95A urethane. For push-force-sensitive applications, spec hardest appropriate wheel.
What about polyurethane-on-steel vs polyurethane-on-aluminum hub?
Same tread, different hub. Aluminum hub is lighter (better for AGV battery life), cooler-running (better for high-speed), and corrosion-resistant. Cast-iron hub is higher load capacity and cheaper. Aluminum hub typically costs 20-35% more; spec for AGV and high-speed; spec cast iron for general-industrial heavy-duty.
Spec the Right Wheel Material
CasterHQ stocks all five wheel materials across the full load and temperature range. Send your load, temperature, floor, and chemical environment. We return a procurement-grade spec with matched tread, hub, bearing, and rig so the wheel survives the full service life of the rack.
References & Standards Cited
- ICWM wheel-material class standards, 2024 edition
- ANSI MH31.1 wheel performance testing specification
- ASTM D2240 durometer reference, ASTM G154 UV weathering
- ASTM D412 elastomer tensile and elongation testing
- CasterHQ 2024-2025 material failure return database, 18,200+ units
- CasterHQ rolling-resistance bench studies 2023-2025, 6 material types
