Castors & Wheels Selection Guides

Swivel castors

Swivel castors have a series of ball bearings in the head that rotate the wheel and forks through 360°. The castors can go in any direction.

Fixed castors

Fixed castors have a plate that fixes the wheel in two directions of travel – forward and backwards.

Braked castors

Total stop braked castors have a locking pedal, when applied both the swivel head and wheel are locked until the pedal is released

Our heavy duty castors are also available with a wheel brake. This type of brake is on the side of the wheel and locks the wheel only.

The same series is also available with a direction lock fitted to the swivel castor, when the lock is applied the castor can only be moved in two directions; back and forth. When the directional lock is “off” the castors function the same as any swivel castor.

Permutations

• 2x fixed castors and 2x swivel castors (or swivel with brake if preferred) fitted to corners of load: The most practical configuration for industrial use. Provides good manoeuvrability and accurate steering, useful on long straight runs. The trolley should be pushed with the fixed castors leading.
• 4x swivel castors (two or four swivel with brake if preferred): Excellent manoeuvrability, suitable for winding runs and where sideways motion is required. However castors with this configuration may be difficult to guide on straight runs particularly with heavy loads or uneven ground.
• 1x swivel castors at each end (or swivel with brake if preferred) and 2x centre fixed castors: Very good manoeuvrability in confined spaces. The fixed castors are either packed or larger by approximately 25mm to pivot the trolley. The load must be evenly distributed to ensure stability.

The load capacity is the total weight to be carried plus the weight of the carrying trolley/truck, divided by the number of supporting castors.

If the load is being carried on a item with four castors we recommend dividing the weight by three to give a good safety margin.

Remember on uneven ground, going over floor tracks, poor surfaces etc not all the castors may be in contact with the floor at a specific time.

As a rule of thumb the larger the wheel diameter the easier it is to move.

A larger wheel diameter will increase the overall height of the trolley/load and that may be critical when trying to marry up heights with existing equipment, benches etc.

Obviously larger castors do cost more.

The common castor fixing types featured in our standard ranges are:

Plate fixing

Normally a rectangular plate for fixing with four bolts. Most of our castors have slotted holes for the bolts to give you some play in lining up. Plate fixing castors are available throughout the ranges. On each page we give the overall plate size and the hole centres.

Single bolt fixing

All our light duty, medium duty institutional and medium duty industrial castors are available in single bolt fixing versions. A single hole is positioned in the centre of the top plate and you pass your loose bolt (not included) underneath the swivel head to fix to the product. Customers select their own loose bolt in a length to suit the application, particularly useful when fixing the steel angle, box section or timber where there isn’t enough space to fit a four hole top plate. Can also be used for fitting to a stud already attached to the product.

Expanding adaptor (expanders)

For fixing up to the inside of round or square section hollow tube, ideal for work trolleys, mobile benches and laboratory equipment, shop displays etc.

Use with single bolt castors – bolt passes underneath castor head, when the bolt is tightened the expanding cone section is pushed out to grip the inside of the tube.

The expanders come in four sizes to suit differing internal tube measurements of both the round and square shaped tube.

For ease of ordering, the light duty and medium duty institutional castors are offered in options complete with expander or you can buy the medium duty castors and expanders as separate items.

Nylon/polypropylene

A hard material, high load capacity to diameter ratio. Lower rolling resistance – easy to push. Impervious to mineral oils and grease. Polypropylene is a similar material to nylon with the same properties and used in our light duty castors range. The disadvantage of nylon can be noise plus vibration and in some heavy load applications possible damage to certain types of floor surfaces.

Rubber

Soft tread, quieter to run and greater floor protection in comparison to nylon. Gives “grip” and less likely to skid on wet surfaces. Rubber does have a greater rolling resistance compared to nylon. Rubber cushions loads, particularly useful over uneven surfaces. Grey and blue rubber tyres are non-marking (black tyres can mark lino etc). Not suitable where there would be contact with oil or grease.

Polyurethane

Combines many of the properties of both nylon and rubber. Comparable load capacity/diameter to nylon but gives some “grip”, also quieter. Polyurethane carries a great load capacity compared to the same diameter rubber castor. Easier to move compared to rubber and less likely to tear. Impervious to mineral oils and grease.

The light duty castors are plain bearing (no bearing fitted the wheel runs on the axle). All our other castors have either a roller or ball bearing this lowers rolling resistance and reduces wear and tear on the wheel.

Stainless steel castors

Suitable for wet and damp areas. Ideal for catering and food processing equipments, medical and clean room environments, marine applications. Choice of three wheel materials in differing diameters and plate or single bolt fixing. See our stainless steel castors range.

High temperature castors

Suitable for effective temperature range -40°C to +270°C. Use anywhere goods have to move to and from changing temperatures – bakeries, ovens, freezers and cold rooms. High temperature castors are available in standard housings and stainless steel versions for use in damp areas

Pneumatic and puncture-proof castors

Both pneumatic and puncture-proof castors are ideal for any rugged or outdoor terrain: nurseries and garden centres, sports equipment, outdoor catering and entertainment products. Will ride over uneven and rough surfaces. Puncture proof castors do what it says on the tin! They have the same properties as pneumatic but without the problem of punctures or flats.

The load capacity is the total weight to be carried plus the weight of the carrying trolley/truck, divided by the number of supporting wheels. We recommend allowing a 25% safety factor, e.g. weight of load and trolley multiplied by 1.25 then divided by the number wheels on the trolley.

The wheel diameter is measured across from one side to the other. As a rule of thumb the larger the wheel diameter the easier it is to move. Larger wheels also tend to have a higher load capacity.

The tread width is the distance across the wheel face that is in contact with the ground surface. The larger the width the greater the contact and grip.

The bore diameter is the size of the hole in the middle of the wheel; you need to check it is compatible with the size of your axle. The bore diameter quoted on the product specification pages is the size of the axle, the hole itself is slightly larger to ensure a good fit.

The hub length is the distance through the centre hole from one side to the other; it needs to be long enough to take all of the axle but not too long otherwise the wheel will be a loose fit.

Hard un-tyred wheels, nylon and cast iron

Hard materials, High load capacity to diameter ratio. Lower rolling resistance – easier to push. Impervious to mineral oils and grease. The disadvantage of these hard materials can be noise and vibration and in some heavy load applications possible damage to certain types of floor surfaces.

Tyred wheels, rubber and polyurethane

Rubber: Soft tread, quieter to run and greater floor protection compared to nylon. Gives “grip” and less likely to skid on wet surfaces but does have a greater rolling resistance. Cushions load, particularly useful over uneven surfaces. Rubber tyres are not suitable where there would be contact with oil or grease. See our rubber tyre wheels range.

Polyurethane: Combines many of the properties of both nylon and rubber. Comparable load capacity/diameter to nylon but gives some “grip”, also quieter. Polyurethane carries a great load capacity compared to the same diameter rubber wheel. Easier to move compared to rubber and less likely to tear. Impervious to mineral oils and grease. See our nylon and polyurethane wheels range.

Pneumatic and puncture-proof wheels

Both pneumatic and puncture-proof wheels are ideal for any rugged or outdoor terrain: nurseries and garden centres, sports equipment, outdoor catering and entertainment products. Will ride over uneven and rough surfaces. Puncture proof wheels do what it says on the tin! They have the same properties as pneumatic but without the problem of punctures or flats.

Plain bearing wheels do not have a bearing in the bore. Roller and ball bearing wheels come with a bearing fitted in the bore, making them smoother running and more manoeuvrable, also reducing wear on the wheel bore.

High temperature castors

Suitable for effective temperature range -40°C to +250°C or +270°C. Use anywhere where goods have to move to and from changing temperatures – bakeries, ovens, freezers and cold rooms.

Pallet truck rollers

Designed as replacements for rollers in pallet truck forks, but also suitable for many other materials handling and live storage applications. Choice of nylon or polyurethane treads.

See our high temperature and pallet truck rollers range.