How to Choose Industrial Castors: Complete Selection Guide
Last updated: March 2026
Quick Answer
Calculate load per castor: Total weight ÷ 3 (for 4-castor setups) = minimum capacity needed. Then choose wheel material based on floor type: rubber for hard floors, nylon for carpet/rough surfaces, polyurethane for heavy loads.
Step 1: Calculate Load Capacity
Formula: (Equipment weight + Maximum load) ÷ 3 = Capacity per castor
Why divide by 3 with 4 castors? Uneven floors mean only 3 castors bear load at any time. This builds in a safety margin.
Example: Trolley (20kg) + Load (180kg) = 200kg total
200 ÷ 3 = 67kg minimum per castor → Choose 75kg or 100kg rated castors
Step 2: Choose Wheel Material
| Material | Best For | Avoid | Capacity |
|---|---|---|---|
| Rubber | Smooth floors, quiet operation, floor protection | Heavy loads, chemicals | Up to 200kg |
| Nylon | Heavy loads, chemicals, outdoor, rough floors | Delicate floors (marks) | Up to 1,000kg |
| Polyurethane | Heavy loads, smooth floors, quiet, no marking | Extreme chemicals | Up to 800kg |
| Cast Iron | Very heavy loads, high temps, durability | Any floor protection needed | Up to 1,500kg |
Step 3: Fixed, Swivel, or Braked?
- 4 swivel: Maximum manoeuvrability in tight spaces
- 2 fixed + 2 swivel: Best for straight runs with steering at one end
- Braked: Essential for workstations, medical equipment, sloped floors
Step 4: Mounting Type
- Plate fitting: Most common, bolts to flat surface
- Bolt hole: Single bolt through centre
- Threaded stem: Screws into socket
- Expanding adaptor: Fits inside tube legs
Frequently Asked Questions
What castor capacity do I need?
Divide total load by 3 (not 4) for 4-castor equipment. This accounts for uneven floors where only 3 wheels touch at once. Always round up to the next capacity rating.
Rubber or nylon wheels?
Rubber for floor protection and quiet running on hard floors. Nylon for heavy loads, outdoor use, and rough surfaces. Polyurethane combines the benefits of both for premium applications.
How do I stop castors marking the floor?
Use non-marking grey rubber or polyurethane wheels. Avoid black rubber on light floors. Increase wheel diameter to reduce pressure on floor surface.
What size castor wheel do I need?
Larger wheels roll more easily and handle obstacles better. As a guide: 50-75mm for light furniture, 100-125mm for trolleys, 150-200mm for heavy industrial equipment.