Swivel Castors & Swivel Castor Wheels.

What are Swivel Castors & Swivel Castor Wheels?

Swivel castors, also known as swivel castor wheels or castor swivel wheels, are the steering half of Accu’s Castors & Wheels range, letting equipment change direction under load without being lifted or dragged. The wheel is carried in a fork that hangs beneath a swivel head, a bearing that lets the whole fork turn through a full 360 degrees beneath its fixing, with the axle set slightly behind the swivel’s centre line. That offset lets the wheel follow whichever way the load is pushed, so a trolley or machine base can be steered round corners, into tight bays and through doorways by hand.

Many of the swivel castors are classified under a European standard: EN 12530 covers institutional settings, EN 12532 industrial equipment moved at up to 4 km/h and EN 12533 industrial equipment moved at 4 km/h to 16 km/h. They are used on almost anything that has to be moved and positioned by hand, from trolleys, platform trucks and mobile workbenches to laboratory apparatus, production equipment, machine bases and heavy transport frames.

How Swivel Castors Work

A swivel castor fixes to the underside of the equipment through a top plate, a single bolt hole or a threaded stem, and the swivel head above the fork turns on a ball race or a precision ball bearing. The wheel’s axle sits a set distance behind the swivel axis, known as the swivel offset, which runs from 18 mm to 60 mm across the range. When the equipment moves, that offset turns the fork so the wheel trails behind its pivot and lines up with the direction of travel, the same self-aligning action seen on a shopping trolley. The circle the castor sweeps as it turns is the swivel radius, from 37 mm to 190 mm, and that space needs to stay clear of the frame and of neighbouring castors.

Picture a platform truck in a distribution centre, carrying up to 600 kg of boxed stock on a 90 kg frame, steered by a swivel pair at the handle end and kept on line by a fixed pair at the front. Spread over three castors, the usual allowance for an uneven floor, the load works out at 230 kg each, within the 250 kg rating of a 125 mm castor whose non-marking elastic rubber tread also protects the sealed warehouse floor. That castor has a swivel radius of 102.5 mm, so each one needs that much clearance around its pivot to spin freely without the fork striking the deck edge or the castor beside it. Without steering at the handle end, the operator would have to drag the truck sideways to turn into each aisle, scuffing the floor and fighting the load.

Materials Swivel Castors Are Made From

In Accu’s swivel castor wheels and housings, engineering-grade metals take the load through the swivel head while the polymer or elastomer tread is matched to the floor and the environment:

• Steel: Pressed steel housings and swivel heads in light to extra-heavy-duty grades, with a blue passivated or zinc plated finish against corrosion.
• Stainless Steel: Swivel housings that stand up to repeated washdown, with the ALPHA STAINLESS castors scoring Excellent (5 of 5) for corrosion resistance.
• Cast Iron: KAPPA swivel housings in cast and forged iron, turning on double row ball races or a taper roller bearing and rated up to 1,440 kg.
• Aluminium: A rigid, low-weight centre for polyurethane and elastic rubber treads, keeping the wheel easy to turn as the castor swivels.
• Rubber: Cushioning treads in solid and elastic rubber, from non-marking compounds for finished floors to a heat-resistant version rated up to 250 °C.
• Rubber - TPR: An 87 Shore A thermoplastic rubber, used on twin-wheel and polyamide-housed swivel castors rated up to 100 kg.
• Plastic - PUR: Injection moulded and cast polyurethane at 40 to 42 Shore D, which turns quietly under load and resists wear on busy swivel castors.
• Plastic - Nylon: Hard polyamide that swivels and rolls with little effort on smooth floors, used for wheels, wheel centres and the silver grey LEVINA housings.
• Plastic - PP: Light polypropylene, moulded as solid wheels for small swivel castors and as centres for rubber and polyurethane treads.
• Plastic - Phenolic: A hard, rigid black wheel, including heat-resistant thermoset versions on stainless steel castors rated up to 280 °C.
• Plastic - TP: Fitted to two stainless steel swivel castors, a black thermoplastic wheel rated at 101.8 kg or 152.9 kg.

Sizes & Types of Swivel Castors Available

Swivel castors in Accu’s range span compact apparatus sizes through to heavy transport units, with the following wheel sizes, fixings and ratings:

• Wheel Diameter (D): 38 mm to 200 mm.
• Wheel Width (T): 16 mm to 50 mm.
• Mounting Height (H): 50 mm to 250 mm.
• Approximate Load Capacity: 25 kg to 1,440 kg.
• Braked/Unbraked: Braked or Unbraked.
• Fixing Type: Bolt Hole Fixing; Rectangular Plate; Square Plate, 60 x 60 mm; Rectangular Plate, EN R42, 105 x 85 mm; Rectangular Plate, EN R43, 137 x 105 mm.
• Plate Fixing Hole Centres (ExG): 36 x 28 mm to 105 x 80 mm.
• Fixing Hole Diameter: 5.3 mm to 11 mm.
• Bolt Hole Diameter: 11 mm or 13 mm.
• Thread Size: M10 x 25 to M12 x 30.
• Swivel Offset: 18 mm to 60 mm.
• Swivel Radius: 37 mm to 190 mm.

Not every fixing covers the full range. Threaded stem castors run from 40 mm to 100 mm wheels, carry up to 120 kg and come with zinc plated housings only, while bolt hole castors cover 50 mm to 125 mm wheels and loads up to 200 kg. Above 200 kg, every castor fixes through a top plate, and heavy-duty swivel castors rated at 500 kg or more all use the EN R43 plate. Swivel offset and swivel radius are listed in the tech spec where available and are worth checking before fitting castors close to a frame edge. Braked versions are also listed under Castors With Brakes and are commonly paired with castors from the Fixed Castors range.

For loads that need to move in any direction across a fixed surface, such as conveyor tables and assembly benches, why not browse Accu’s Mini Ball Transfers and Long Life Heavy Duty Ball Transfers instead, which let the load roll over them in every direction.

FAQ

Q: What is a swivel castor?

A: A swivel castor is a wheel mounted in a fork that can rotate through a full 360 degrees beneath its fixing, so the equipment it carries can be steered in any direction. The axle is set slightly behind the swivel axis, so the wheel automatically trails into line with the direction of travel. In Accu’s range they fix with a top plate, a bolt hole or a threaded stem and carry from 25 kg to 1,440 kg each.

Q: Do swivel castors go on the front or back?

A: On a trolley that is pushed from one end, the swivel castors usually go at the handle end with fixed castors at the far end, so the operator steers from where they push while the fixed pair keeps the trolley tracking straight. Equipment that is pulled or towed is often set up the other way round, with the swivels leading. Where equipment has to turn on the spot in a tight space, four swivel castors give the greatest manoeuvrability, usually with at least two braked so it can be held in position.

Q: What is the difference between swivel castors and fixed castors?

A: A swivel castor’s fork rotates through 360 degrees so it can steer, while a fixed castor’s fork is locked in one direction so it only rolls forwards and backwards. One makes equipment manoeuvrable while the other keeps it tracking straight and stops it drifting sideways, which is why the two are so often combined on the same trolley. Fixed castors also have no swivel radius to allow for, so they need less clearance under the frame.

Q: What are the two main types of castors?

A: By movement, the two main types are swivel castors and fixed castors, which are also called rigid castors. By mounting, castors either fix through a top plate bolted to the underside of the equipment or through a single point, such as a threaded stem or a bolt hole, which suits narrow legs and tubular frames. Accu’s swivel range is available with all three fixings, although plate fixing is the choice for heavier loads, and every castor in it rated above 200 kg uses a top plate.

Bespoke Swivel Castors & Swivel Castor Wheels Manufacture.

High precision, bespoke manufacture of Swivel Castors & Swivel Castor Wheels to customer specification. State of the art facilities specialising in both small batch prototyping and large scale manufacture.