How to choose the right castor

A trolley's load capacity is not simply the sum of the capacities of the castors fitted. It depends on how many there are and how they're arranged.

Our range covers 418 castors across Easyroll and Colson, from 40kg per castor on the Easyroll 50mm G1 series to 2000kg on the X1 series, which runs a urethane tread on a cast iron wheel. EHI is part of the Colson Group, which describes itself as the largest castor and wheel maker in the world.

Work out the load on each castor first. Wheel size, material and bearing are all chosen against that figure.

1.Start with the load on each castor

The instinct on a four-wheel trolley is to divide the total by four. On a level floor with an even load that holds - each castor carries 25% of the total. On an uneven floor one castor can lose contact and three carry the lot, which means a castor sized for a quarter is now overloaded. The catalogue rates each castor for 35% of the total load to allow for that.

Total load is the weight of the trolley plus what it carries. A 120kg cage carrying 800kg of stock is a 920kg total load. How much of that lands on each castor depends on the layout, and the table below gives the share for each one.

Put the 920kg cage on four castors and each one needs a rating of at least 322kg, which is the 35% share. The calculator below runs the same sum for any layout and links to the load band your figure falls in.

The catalogue ratings are what each castor carries on an average floor at speeds up to 4 km/h. Faster, powered or towed work and rough ground need headroom on top of that figure. Castor maker Blickle builds that headroom in as a safety factor, which multiplies the load per castor to allow for conditions beyond the standard ones (a smooth floor, walking pace, an even load, travelling straight, 15°C to 28°C). Blickle's factor rises with speed and with the height of obstacles against the wheel diameter - 1.0 to 1.5 pushed by hand indoors, up to 2.0 to 3.0 motorised outdoors. The optional speed and duty step in the calculator above (x1.5 for powered or towed work, x2.0 for high speed, impact or shock) puts that kind of headroom on the catalogue figure.

For an easier push, WorkSafe Victoria's advice is large castors and wheels that roll freely. A precision bearing helps, and so does a wheel no softer than the floor needs. The regulator's force figures are in the trolley guide.

2.Match the wheel material to the floor, and to what's on it

Colson I3 · 250kgred urethane, the all-rounderShop this castor

The wheel material is chosen from the floor and what's on it - a finished floor, bare concrete, broken glass, an oven floor, rough ground. It decides how the castor treats the floor, how easily it pushes and how much shock it soaks up.

Polyurethane is the best all-round choice, so it's our default when nothing about the floor rules it out. The range is spread wider than that - about a quarter of it is polyurethane, then thermoplastic rubber (TPR), rubber, nylon, cast iron and pneumatic. TPR has no rating in the catalogue, but it's the biggest single material in the medical castors and makes up over half the shopfitting castors. The table below rates the rest.

Cast iron is best for high temperature, and the polyurethane tread on the X2 series is rated -20°C to +85°C, so check the series before a castor goes under an oven or into a freezer. Where kit sits loaded for long spells, ask us about the castor's static load capacity. Static load is a separate test under ISO 22878, and one thing it checks is how far the tread flattens over time.

PolyurethaneShop NylonShop RubberShop Cast ironShop PneumaticShop Puncture-free wheelsShop

3.Match the bearing to how often, and how fast, it moves

Colson I3 · 230kgball bearing, total lockShop this castor

Plain bearings are harder to push, so they suit equipment that won't be moved much. Under normal conditions they're maintenance free and corrosion-resistant, and they pair well with nylon wheels, which lubricate themselves.

Roller bearings need little maintenance and run needle rollers in a cage, so the friction is rolling rather than sliding. The resistance stays relatively low even at high loads, which suits heavy equipment moved by hand.

Ball and precision bearings carry about three quarters of the range - 309 of the 418 castors run on one or the other. Ball bearings are on 226 of those castors, and they're compact, simple units. Blickle notes a ball-bearing castor can run faster than 4 km/h at a reduced load capacity, so if the kit goes faster than walking pace, set the duty step in the calculator. Precision bearings are sealed and lubricated for life, and they keep running easily under extreme loads and at high speeds. For equipment pushed all day or towed, precision is the pick.

4.Configuration and mounting

Colson I6 · 180kgblue rubber, swivel plateShop this castor

Which castors swivel sets the steering. Fixed castors hold a line and swivel castors follow the push. WorkSafe Victoria points out that a swivel castor not facing the direction of travel takes extra force until it lines up. A directional lock lets a swivel line up and then holds it there, which can help push a trolley in a straight line down a busy corridor. The offset is the gap between the swivel's pivot and the wheel's axle. It's why a swivel wheel trails its pivot and turns with less scrub on the floor. A six-wheel rocking layout sets the fixed centre pair 12mm to 25mm higher than the corners, so the trolley rocks onto either end - very good for manoeuvrability, but the centre pair needs higher-rated castors, which is the 50% centre row in the load table above.

A wheel brake stops the wheel turning, but the castor still swivels. A total lock stops both the swivel and the wheel, and the catalogue calls it the safest of all brake types. The catalogue warns that wheel-braked castors should never be fitted to a bench or table carrying power tools or cutting instruments, because even with the brakes on, the table can move up to twice the castor's offset - on a 200mm castor that can be 100mm to 150mm, without warning. A bench like that gets total locks.

Plate mount is the most common fitting in the range (274 of 418), then bolt hole, socket, expanding pintle and threaded stem. The fitting matches the frame - the plate size and hole centres, or the stem thread. A plate castor's spec table lists the plate dimensions and, on most, the hole centres, so measure the frame before ordering. For tube frames, the accessories range carries expanding adaptors in M10 and M12 for 19mm, 22mm and 27mm round and square tube, and M10 and M12 x 75mm stem adaptors.

SwivelShop FixedShop BrakedShop Plate mountShop Bolt holeShop Threaded stemShop SocketShop AccessoriesShop

5.Compliance, by environment

Colson FS · 100kgdual lock, medical & institutionalShop this castor

The castor standards set how a castor is tested and rated - ISO 22878 for the test methods, ISO 22881 for institutional use and ISO 22883 for industrial castors up to 4 km/h.

Medical and hospital equipment

IEC 60601-1 covers medical electrical equipment as a whole, not a castor part number. Clause 9.4.2.4.2 caps the force to move mobile medical electrical equipment at 200 N, and clause 9.4.3.2 asks for wheel locks or a braking system. That points to large, free-rolling castors with locking brakes. Of our 75 medical castors, 42 carry a total-lock brake, and thermoplastic rubber is the most common wheel.

Food, pharma and washdown areas

Food, pharma and washdown areas take the stainless steel castors - 54 of them, most on polyurethane, TPR or nylon wheels. Of the 54, 33 run on ball bearings. The 12 on precision bearings are sealed, so their lubrication lasts for life even in harsh conditions, and the 9 on plain bearings are corrosion-resistant under normal conditions. If the job calls for a particular stainless grade or has to stand a cleaning chemical, ask us.

Static-sensitive areas

Static-sensitive areas want a castor that lets a static charge dissipate safely. Blickle treats a wheel or castor as electrically conductive if its resistance does not exceed 10⁴ ohms and as antistatic if it does not exceed 10⁷ ohms, tested in line with EN 12527. Our catalogue offers an electrically conductive wheel on the H7 series (hospital and operating-table castors). Nothing conductive or antistatic is listed online.

Australian workplaces

Safe Work Australia's model Hazardous Manual Tasks code works by risk assessment, and it names reviewing castor types, sizes and arrangements as one way to cut the effort of starting a load.

Standards get revised, so confirm the current edition before you design to a figure from one.

6.Castors for your industry

Colson X1 · 2000kgurethane on cast iron, the heavy endShop this castor

We supply castors across Australian industry. To start from the job instead of the part, choose your industry below.

Manufacturing & EngineeringMachine bases and workshop trolleys. Polyurethane and cast iron wheels, most on ball bearings.Heavy duty castors Warehousing & LogisticsPickers and cages. Ball bearings throughout, total-lock options.Ball bearing castors Food & BeverageWashdown and hygiene. Stainless, sealed bearings, nylon or TPR wheels.Stainless castors Healthcare & Aged CareQuiet movement, safe parking. TPR wheels, total-lock, low push force.Medical castors Mining & ResourcesHeavy and abrasive. Cast iron, or urethane on cast iron, to 2000kg per castor.Super heavy duty Construction & InfrastructureRough, broken ground. Pneumatic castors, for irregular or unsealed surfaces.Pneumatic castors Retail & HospitalityShopfitting, display and back-of-house. Light, quiet and floor-friendly.Shopfitting castors AgricultureYards and sheds. Pneumatic and puncture-free wheels.Puncture-free wheels

7.How to order

Over the phone

Have these to hand before you call.

1. Load - the total weight (gear plus what it carries), or the load per castor if you've worked it out, and how many castors.
2. Wheel diameter - in mm, or in inches if that's how your equipment's dimensioned. Bigger rolls easier.
3. Wheel material - or just tell us about the floor and what's on it, and we'll pick.
4. Bearing - or how often and how fast it moves, and we'll match it.
5. Brake - none, wheel, directional or total lock.
6. Mount - plate, bolt hole or stem, with the plate size and hole centres, or the stem thread. Measure what's there now, or send a photo.
7. Environment - washdown, chemical, heat, static, outdoor, medical. This one overrides the defaults.

On the site

All of that maps onto the filters on the castor range, so you can spec it yourself:

1. Open the castor range and set the load-capacity filter to the band the calculator gave you.
2. Add the filters that matter for the job - wheel material, diameter, bearing, brake, mount. The grid narrows to castors that meet the lot at once.
3. Open a product and read the spec: the full load rating, the wheel and bearing detail and the dimensions sit in the spec table, and the datasheet PDF is on the same page.
4. Log in for your account pricing and order, or call us for an account and pricing for your first order.

Standards reference

If you need to cite a standard, this is where each one stands.

• AS 1961 series - withdrawn by Standards Australia; its parts adopted the ISO set (AS 1961.2 = ISO 22878, AS 1961.5 = ISO 22881, AS 1961.7 = ISO 22883) - specify to the ISO set.
• ISO 22877 to 22884 - test methods and requirements by application: institutional, industrial up to 4 km/h, and industrial from 4 km/h to 16 km/h.
• EN 12527 to 12533 - the European castor standards. Blickle lists them alongside ISO 22878 to 22884 and tests its castors to them on a rotating bench.
• IEC 60601-1 - medical electrical equipment: 200 N to move it (clause 9.4.2.4.2), wheel locks or a braking system (clause 9.4.3.2).
• Electrostatic classes - Blickle's figures: conductive at no more than 10⁴ ohms, antistatic at no more than 10⁷ ohms, in line with EN 12527.

The castor brands we carry

Every castor in the range is an Easyroll or a Colson.

Take the calculator's figure to the castor range, set the load band and narrow the castors down for the job, then check the castor you choose is rated for at least that figure, as the band can start below it.