Castors

What are castors?

Castors are wheels mounted in a bracket that are fitted to the underside of trolleys, carts, machinery, furniture, and equipment so they can be moved easily. A castor combines a wheel, an axle, and a mounting bracket, often with a swivel head that lets the wheel turn in any direction. Fitting castors turns heavy or awkward items into mobile ones, making it easier and safer to move them around workshops, warehouses, kitchens, offices, and homes.

Castors are usually described by their wheel diameter, such as 40 mm, 3 inch, or 4 inch, along with their type, wheel material, mounting method, and load capacity.

A typical plate-mounted castor has:

• Wheel - the rolling part, often a rubber tyre on a steel or plastic centre
• Axle - the bolt or pin that the wheel turns on
• Bracket (fork) - holds the wheel and axle and connects them to the mounting plate
• Swivel head - on swivel castors, a ball race that lets the bracket turn through 360 degrees
• Top plate - a flat plate with bolt holes for fixing the castor to the underside of the item
• Brake - on braked castors, a lever that locks the wheel to stop it rolling

Key features:

• Easy movement - makes heavy and bulky items simple to push and manoeuvre
• Swivel or fixed - swivel castors steer in any direction, while fixed castors roll in a straight line
• Brake options - braked castors hold equipment in place when parked
• Rubber wheels - give quiet, smooth running and help protect floors
• Plated steel brackets - strong and resistant to corrosion
• Simple fitting - top plates bolt or screw directly to trolleys, platforms, and equipment
• Range of sizes - small castors for light furniture and equipment, larger castors for trolleys and machinery

In simple terms, castors are wheels that make equipment mobile, allowing it to be moved, steered, and parked easily.

Why are castors essential?

Castors are essential because moving heavy or bulky items by hand can be difficult, slow, and unsafe. Lifting and carrying equipment can cause back injuries and strains, and dragging items can damage floors and the items themselves. Fitting the right castors lets one person move loads smoothly and safely, making workplaces more efficient and flexible.

Their main benefits are:

• Safer handling - reduces the need to lift and carry heavy items, lowering the risk of injury
• Improved efficiency - moves equipment and materials quickly around the workplace
• Flexibility - allows equipment to be repositioned, cleaned around, or stored away easily
• Better control - combinations of swivel and fixed castors make steering easier
• Secure parking - braked castors stop equipment rolling when it needs to stay in place
• Floor protection - rubber wheels help protect floors from scratches and marks
• Quieter movement - rubber wheels reduce noise compared with harder wheels
• Cost-effective - an inexpensive way to make equipment mobile

Castors are used across a wide range of industries and applications, including:

• Trolleys and carts - platform trolleys, tool trolleys, and service carts
• Workshops and garages - workbenches, tool chests, welding carts, and machinery stands
• Warehouses and logistics - dollies, cages, and handling equipment
• Industrial machinery - mobile machines, stands, and equipment bases
• Catering and hospitality - kitchen trolleys and serving carts
• Healthcare and laboratories - equipment trolleys and mobile stands
• Retail - display stands and stock trolleys
• Furniture and DIY - mobile storage, workbenches, plant stands, and home projects

The main types of castors

Castors are usually grouped by their movement, wheel material, mounting method, and size.

By movement:

• Swivel castors - the bracket turns through 360 degrees, allowing the item to be steered in any direction. Ideal for tight spaces and easy manoeuvring
• Fixed castors - the wheel rolls in a straight line only, giving better directional control and stability when pushing in a straight line
• Braked swivel castors - swivel castors with a brake lever that locks the wheel, holding the equipment in place when parked
• Total lock castors - lock both the wheel and the swivel, giving the most secure parking

Common castor layouts:

• Two swivel and two fixed - the most common layout for trolleys, combining easy steering with good straight-line control
• Four swivel - gives maximum manoeuvrability, ideal for tight spaces, with braked castors added for parking
• Four swivel with two braked - easy to steer and can be parked securely

By wheel material:

• Rubber wheels - quiet, smooth, and good at absorbing shock, while protecting floors. A popular choice for general use
• Polyurethane wheels - hard-wearing, non-marking, and roll easily under higher loads
• Nylon and polypropylene wheels - hard, strong, and resistant to chemicals and moisture, rolling easily on smooth floors, though noisier on rough surfaces
• Pneumatic wheels - air-filled tyres for rough or uneven ground
• Cast iron and steel wheels - for very heavy loads and high temperatures

By mounting method:

• Top plate castors - have a flat plate with bolt holes, fixed with bolts or screws. The most common type for trolleys and equipment
• Bolt hole castors - have a single hole in the top for fixing with a bolt
• Threaded stem castors - have a threaded stem that screws into a tapped hole or insert
• Socket or grip neck castors - push into a socket fitted in the leg of furniture or equipment

By size:

• Small castors - such as 40 mm wheels, ideal for light furniture, small trolleys, and equipment
• Medium castors - such as 3 inch and 4 inch wheels, suitable for general trolleys, workbenches, and workshop equipment
• Large castors - 5 inch and above, for heavier loads, rough floors, and easier rolling over obstacles

How to choose the right castors?

Choosing the right castors means matching them to the load, the floor, and how the equipment will be moved. Work through these points in order:

• Load capacity - work out the total weight of the item and its maximum load. As a guide, divide the total weight by three rather than four, as one castor may not always be in full contact with the floor on uneven surfaces
• Wheel diameter - larger wheels roll more easily and cope better with uneven floors, cracks, and cables, while smaller wheels keep the item lower to the ground
• Swivel, fixed, or braked - choose swivel castors for manoeuvrability, fixed castors for straight-line control, and braked castors for secure parking
• Castor layout - choose a layout that suits how the item is moved, such as two swivel and two fixed for trolleys, or four swivel for tight spaces
• Floor type - choose rubber or polyurethane wheels for smooth or delicate floors, and harder wheels for heavy loads on smooth floors
• Wheel material - consider noise, floor protection, rolling ease, and resistance to chemicals and moisture
• Mounting method - choose top plate, bolt hole, or threaded stem castors to suit the item, and check the plate size and bolt hole positions
• Overall height - check the total height of the castor to make sure the item ends up at the right working height
• Environment - choose corrosion-resistant brackets and suitable wheels for wet, outdoor, or washdown areas
• Frequency of use - choose heavier-duty castors with better bearings for items that are moved often
• Quality and brand - choose castors from reputable suppliers for reliable load ratings and long service life

FAQ - All you need to know about castors

What is the difference between a swivel and a fixed castor?

A swivel castor can turn through 360 degrees, allowing the item to be steered in any direction. A fixed castor only rolls in a straight line, giving better directional control.

What castor layout should I use on a trolley?

The most common layout is two swivel castors and two fixed castors, which gives easy steering and good straight-line control. Four swivel castors give maximum manoeuvrability, and adding brakes allows the trolley to be parked securely.

How do I work out the load capacity I need?

Add up the weight of the item and the heaviest load it will carry. Then divide by three rather than four, as on uneven floors one castor may not always carry its share of the load. Choose castors with a capacity at or above that figure.

What size castor do I need?

Choose a wheel size that suits the load, floor, and height. Larger wheels roll more easily over rough floors and obstacles, while smaller wheels suit light items and keep them low to the ground.

Are rubber wheels good for all floors?

Rubber wheels are quiet, smooth, and floor-friendly, making them ideal for most indoor floors. For very heavy loads or chemical exposure, polyurethane or nylon wheels may be more suitable.

What is a braked castor?

A braked castor has a lever that locks the wheel, stopping it rolling so equipment stays in place. Total lock castors lock both the wheel and the swivel for maximum stability.

How do I fit plate-mounted castors?

Position the castor so the top plate sits flat against the underside of the item, then fix it with bolts, nuts, and washers, or suitable screws through all the plate holes. Make sure the mounting surface is strong enough to carry the load.

Why does my trolley pull to one side?

Common causes include a worn, damaged, or seized wheel, a bent bracket, uneven castor heights, or debris wrapped around a wheel or axle.

How do I look after my castors?

Keep wheels and swivels free from dirt, hair, and debris, check fixings regularly, and lubricate swivel heads and wheel bearings occasionally where possible. Replace castors with worn, cracked, or flat-spotted wheels.

Can castors be used outdoors?

Yes, but choose castors with corrosion-resistant brackets and wheels suited to the ground, such as larger or pneumatic wheels for rough or uneven surfaces.