In the process of selecting casters, many people pay more attention to the load capacity, but they tend to overlook a crucial parameter – the caster diameter. In fact, the diameter of the caster is directly related to its load capacity, smoothness of movement, stability, and applicable scenarios. Choosing the right diameter can make equipment movement much easier; choosing the wrong one can affect efficiency and even safety.
This article will systematically analyze the impact of caster diameter from the perspectives of common specifications and practical use.
1. Common classification of caster diameter specifications
The size of casters is typically distinguished by the diameter of the wheel, with common units being millimeters (mm) or inches (inch). Based on the diameter size, casters can be roughly divided into the following categories:
Small casters (25–75mm)
With its small size and high flexibility, it is suitable for lightweight equipment or applications with high steering requirements, but its load-bearing capacity is limited.
Medium-sized casters (100–150mm)
Balancing load-bearing capacity and flexibility, it is suitable for medium-weight equipment and covers a wide range of sizes.
Heavy-duty casters (150–200mm)
It has strong carrying capacity, suitable for heavier equipment, requires less effort to move, and has better adaptability to different ground conditions.
Extra-heavy duty casters (over 200mm, some up to 350mm)
Used for special working conditions or overweight equipment, it emphasizes load-bearing and passing performance, and has high requirements for space.
2. The critical impact of caster diameter on performance
1). Bearing capacity
Under the premise of identical structure and material, the larger the caster diameter, the stronger the load-bearing capacity is usually. Larger wheels can distribute weight more evenly, reducing localized stress and thus increasing the overall load limit.
2). Mobility and adaptability to ground conditions
In environments with uneven ground, numerous gaps, or obstacles, large-diameter casters are more likely to “surmount” obstacles, roll smoother, and reduce impact and damage to the ground.
3). Mobility stability
Caster wheels with a larger diameter typically exhibit better stability during heavy loads or high-speed movement. This is because large wheels possess greater rotational inertia, making them less prone to significant wobbling caused by minor obstacles or vibrations.
4). Matching the usage environment
Different usage environments have different requirements for the diameter of casters. For example:
* For frequent movement of equipment within warehouses or factories, medium to large diameter casters are suitable to reduce the pushing resistance
* For outdoor or rough ground, a larger diameter is needed to enhance the trafficability
* In situations where space is limited and equipment needs to be lightweight, small-diameter casters are more suitable
5). Equipment structure and installation space
The diameter of the casters is not necessarily the larger the better. It is also necessary to consider the height of the equipment itself, structural design, and the available installation space. An excessively large diameter may affect the overall height or stability of the equipment.
3. How to reasonably select the diameter of casters?
The selection of caster diameter is essentially a comprehensive trade-off between load capacity, environmental factors, stability, and spatial conditions. When selecting a model, the following issues should be considered for judgment:
What is the total weight of the equipment?
*Is the ground used flat and level?
*Is frequent movement or long-distance pushing required?
Is there a limitation on installation space?
Only when all these conditions are met can the casters perform optimally.
Conclusion
Although the diameter of the castor is just a parameter, it plays a decisive role in practical use. Reasonably selecting the diameter of the castor can not only improve the mobility efficiency but also extend the overall service life of both the castor and the equipment. Taking an extra step in the selection phase can often avoid the trouble of frequent replacement and maintenance in the later stages.
If you need, I can also help you further adapt it into a “Quick Reference Table for Model Selection” version, or split it into multiple articles based on light/medium/heavy load application scenarios.
Post time: Jan-17-2026
