A castor wheel is a relatively small undriven wheel, meaning that it is free-rolling (as opposed to powered). They are designed to be attached to the bottom of a larger object, to enable easy movement across a floor or other hard surface.
Castor wheels are often referred to simply by the standalone term ‘castors’. They are also commonly identified as ‘caster wheels’ or ‘casters’ by some suppliers and manufacturers. The latter spelling is perfectly valid, although it is largely a US variant. The preferred standard is usually ‘castor’ in the UK.
So, what exactly are castor wheels?
In terms of basic form, there are three main types of castors. They will usually be manufactured in either a single wheel, a double wheel, or a compound wheel configuration:
- A double wheel castor aligns two separate twin wheels side-by-side, for better stability
- Compound castors are two-piece single wheels, made from fixed concentric discs that rotate together around one axis. This can potentially offer greater overall strength in load-bearing applications
Most castor wheels in the UK are relatively simple components. They can be found attached to ‘vehicles’ (typically furniture or basic machinery) in a great many domestic and commercial settings. As a result, many different options and styles are available.