Caster Load Rating Chart by Wheel Material
Load ratings vary significantly by wheel material, wheel diameter, rig type, and bearing quality. This reference chart provides load rating ranges by material and size to help you select the right caster for your application. Always verify specific load ratings in the product specification, these charts show typical ranges, not absolute values.
How to Use This Chart:
- Calculate your required load per caster: (Cart weight + Max load) / Number of casters x Safety factor
- Determine your environment (floor type, temperature, chemical exposure) to identify appropriate wheel materials
- Find the wheel material and size combination that meets or exceeds your calculated load requirement
- Always select the next capacity level up, not the exact calculated minimum
Polyurethane Caster Load Ratings
Polyurethane is available in durometers from 70A (soft) to 95A (firm). Higher durometer = higher load capacity.
| Wheel Diameter | Wheel Width | Load Rating Range |
|---|---|---|
| 2" | 3/4" | 75-150 lbs |
| 3" | 3/4" | 100-250 lbs |
| 3" | 1-1/4" | 150-300 lbs |
| 4" | 1-1/4" | 200-400 lbs |
| 4" | 1-1/2" | 250-500 lbs |
| 5" | 1-1/4" | 300-600 lbs |
| 5" | 2" | 400-900 lbs |
| 6" | 2" | 500-1,100 lbs |
| 8" | 2" | 600-1,200 lbs |
Nylon Caster Load Ratings
Harder than polyurethane with excellent chemical resistance. Higher loads at equivalent sizes.
| Wheel Diameter | Wheel Width | Load Rating Range |
|---|---|---|
| 3" | 1-1/4" | 150-300 lbs |
| 4" | 1-1/4" | 250-500 lbs |
| 5" | 1-1/2" | 400-900 lbs |
| 6" | 2" | 600-1,200 lbs |
| 8" | 2" | 750-1,400 lbs |
Phenolic Caster Load Ratings
Among the highest load-rated organic wheel materials. Temperature resistant to 250°F.
| Wheel Diameter | Wheel Width | Load Rating Range |
|---|---|---|
| 3" | 1-1/4" | 175-350 lbs |
| 4" | 1-1/2" | 350-700 lbs |
| 5" | 2" | 600-1,100 lbs |
| 6" | 2" | 700-1,200 lbs |
| 8" | 3" | 1,000-1,500 lbs |
Rubber Caster Load Ratings
Lower load ratings than polyurethane or nylon. Best for noise reduction, shock absorption, and floor protection.
| Wheel Diameter | Wheel Width | Load Rating Range |
|---|---|---|
| 3" | 1" | 100-175 lbs |
| 4" | 1-1/4" | 150-300 lbs |
| 5" | 1-1/2" | 200-450 lbs |
| 6" | 2" | 300-600 lbs |
Steel Caster Load Ratings
Highest loads and highest temperatures. Ratings vary by wheel construction (stamped, forged, cast iron).
| Wheel Diameter | Wheel Width | Load Rating Range |
|---|---|---|
| 3" | 1" | 250-500 lbs |
| 4" | 1-1/4" | 400-800 lbs |
| 5" | 1-1/2" | 600-1,200 lbs |
| 6" | 2" | 800-1,500 lbs |
| 8" | 2" | 1,200-2,000 lbs |
| 10" | 3" | 1,500-3,000 lbs |
Pneumatic Caster Load Ratings
Lower loads than solid wheels at equivalent sizes. Load rating assumes correct inflation pressure.
| Wheel Diameter | Wheel Width | Load Rating Range |
|---|---|---|
| 8" | 2-1/2" | 300-500 lbs |
| 10" | 3" | 400-700 lbs |
| 12" | 3-1/2" | 500-900 lbs |
| 16" | 6" | 800-1,200 lbs |
How to Use This Reference
Safety Factor Guide: Apply a safety multiplier to your calculated load per caster. Use 1.25x for smooth floor, controlled loading. Use 1.5x for moderate floor variation or impact. Use 2.0x for heavy impact or rough floors.
Load Rating Impact by Rig Type: The swivel rig design also affects load capacity. Standard kingpin swivel casters provide the baseline rating and are appropriate for loads under approximately 800 lbs. Kingpinless (raceway) swivel casters are rated 25-50% higher, distributing load through the full raceway. Rigid (fixed) casters have slightly higher ratings than equivalent swivels since there is no swivel mechanism to fail.
Load Rating Warning Signs (Your Casters Are Overloaded): Flat spots appearing on wheels within weeks of installation. Swivel rigs wobbling or kingpin nuts backing off frequently. Wheel tread cracking or splitting at the hub bonding line. Swivel rig deforming or tilting out of vertical. Caster failure at the axle bolt or plate bolt connection. If you see any of these, recalculate your load per caster and upgrade to the next capacity level.
Quick Reference
Rubber: 175-400 lbs
Polyurethane (soft, 70A-80A): 300-500 lbs
Polyurethane (firm, 85A-95A): 450-900 lbs
Nylon: 350-900 lbs
Phenolic: 400-1,000 lbs
Steel: 600-1,200 lbs
Smooth floor, controlled loading: 1.25x safety factor
Moderate floor variation or impact: 1.5x safety factor
Heavy impact, rough floors: 2.0x safety factor
Standard kingpin swivel: Baseline rating, appropriate for loads under ~800 lbs
Kingpinless (raceway) swivel: 25-50% higher than kingpin, distributes load through full raceway
Rigid (fixed) caster: Slightly higher than equivalent swivel, no swivel mechanism to fail
Double ball bearing swivel: Intermediate, improved over single bearing but below kingpinless
Need Help with Your Caster Order?
Visit the resources linked below including everything you need to get you started!