Recommended Castor Load Capacity Guide
Selecting the correct castor load capacity is essential for safe movement, long service life and reliable equipment performance.
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How to Calculate Castor Load Capacity
To determine the correct castor load rating, calculate the total gross weight of the equipment:
Transport Equipment Weight + Maximum Load
The total weight should then be divided according to the castor configuration being used.
⚠️ Important: Unless otherwise stated, castor load capacities are based on manual movement at walking speed, up to 4 km/h. Powered towing applications require specialist castors designed for higher operating speeds and dynamic loading.
Factors That Affect Castor Load Capacity
Several operating conditions can increase the load placed on individual castors.
Uneven Floors
Cracks, potholes, expansion joints, drainage channels and kerbs can create shock loading and uneven weight distribution.
Uneven Weight Distribution
During movement, some castors may temporarily lift away from the floor, transferring additional weight onto the remaining castors.
Shock Loading
Dropping loads onto equipment, even from a small height, can significantly increase the force applied to the castors.
⚠️ Important: For this reason, a safety margin should always be included when selecting castors.
Common Castor Configurations
A castor configuration refers to:
- The number of castors
- Their position
- Whether fixed or swivel castors are used
The configuration directly affects load distribution, manoeuvrability, stability and steering performance.
4-Castor Configuration
The most common setup uses:
- 2 swivel castors
- 2 fixed castors
In this arrangement, each castor should support at least:
(Transport Equipment Weight + Maximum Load) ÷ 3
This means each castor should be rated for approximately one-third, or 33%, of the total gross weight to allow for uneven loading conditions.
3-Castor Configuration
Three-castor layouts are typically used for lightweight equipment, compact trolleys and circular platforms.
Each castor should support at least 40% of the total gross weight.
⚠️ Important: Three-castor configurations are generally recommended only for lighter-duty applications.
6-Castor Configuration with Central Fixed Castors
Long platform trolleys sometimes use:
- 2 larger central fixed castors
- 4 outer swivel castors
The central castors are often slightly taller to create a pivot point and improve manoeuvrability.
Recommended load distribution:
- Central fixed castors: minimum 50% of gross weight each
- Outer castors: minimum 33% of gross weight each
This configuration improves steering performance on long transport platforms.
Jacking & Levelling Castors
Jacking castors and Footmaster levelling castors are designed to lift equipment, stabilise machinery and provide adjustable levelling.
⚠️ Important: Because lifting forces can place additional load onto individual castors, each castor should support at least:
(Transport Equipment Weight + Maximum Load) ÷ 2
This allows for the increased loading generated during lifting and levelling operations.
Summary
When selecting industrial castors:
- Calculate load capacity per castor, not per set
- Include both equipment weight and payload
- Allow for uneven floor conditions
- Include a safety margin
- Consider shock loading and operating conditions
- Match the castor configuration to the application
Correct load capacity selection improves safety, manoeuvrability, castor lifespan and equipment reliability.
