Plastic Castors.

What are Plastic Castors?

Plastic castors, also known as plastic wheel castors, are the hard-wearing, easy-rolling part of Accu’s Castors & Wheels range, using polyamide, polyurethane, polypropylene or phenolic wheels to move loads with minimal effort on smooth, hard floors. They are recognisable by a solid, rigid wheel or firm tread, in natural, white, honey yellow, silver grey, red, blue or black, with no soft rubber tyre around the outside. A hard wheel deforms very little under load, so it starts rolling with less force than rubber, typically carries more on the same size of wheel and stands up well to a busy production floor.

European castor standards apply across much of the plastic range, from EN 12528 (furniture) and EN 12530 (institutional settings) through to EN 12532 (industrial use up to 4 km/h) and EN 12533 (industrial use from 4 km/h to 16 km/h). They are used across manufacturing, logistics and engineering, from small instrument cases and light apparatus to warehouse trolleys, production line carts and heavy transport frames.

How Plastic Castors Work

Fitting a plastic castor is no different from fitting any other, whatever the fixing, but the wheel material is what shapes how it performs. Solid polyamide at 75 Shore D barely flattens under load, so its rolling resistance is very low and it can carry the most weight for its size, while cast or injection moulded polyurethane at 40 to 42 Shore D gives slightly at the contact patch for better grip and gentler running on finished floors. Because the wheel is hard, debris and floor joints are felt more than on rubber, which is why plastic wheels work best on smooth, clean floors. The wheel centre matters too, with polyurethane ratings climbing from 40 kg to 60 kg on a polypropylene centre to as much as 1,200 kg on a cast iron one.

On an automotive assembly line, a kitting trolley loaded with 240 kg of parts on a 60 kg frame is pushed between the stores and the line many times a shift across sealed concrete. On the usual three-castor basis, that is 100 kg per castor, leaving plenty of margin on the 150 kg rating of an 80 mm castor with an injection-moulded polyurethane tread. The low rolling resistance keeps the push force down for operators repeating the same move all day, while the polyurethane tread protects the sealed floor and its wear resistance, rated Very Good (4 of 5), keeps the wheels round for longer. An 80 mm solid rubber castor in the same housing is rated at only 70 kg, well short of this load.

Materials Plastic Castors Are Made From

Accu’s plastic castors use engineering-grade polymers for the wheel, set in metal housings chosen for the load and the working environment:

• Plastic - Nylon: Solid polyamide wheels and wheel centres at 65 to 75 Shore D, with very low rolling resistance and loads from 25 kg on the smallest castors up to 1,440 kg on the extra-heavy-duty KAPPA wheel.
• Plastic - PUR: Injection moulded and cast polyurethane treads at 40 to 42 Shore D, giving more grip and gentler running than solid polyamide, with cast versions on aluminium and cast iron centres rated up to 1,200 kg.
• Plastic - PP: Light polypropylene, used as a solid wheel on small castors rated 25 kg to 50 kg and as a wheel centre beneath polyurethane treads.
• Plastic - Phenolic: A hard thermoset family covering black phenolic wheels at 100 kg to 150 kg and heat-resistant wheels for 250 °C and 280 °C service.
• Plastic - TP: A tough black wheel used on stainless steel castors rated at 101.8 kg and 152.9 kg.
• Steel: Pressed steel forks and plates in light to extra-heavy-duty grades, protected by blue passivation or zinc plating and carrying most of the plastic wheels in the range.
• Stainless Steel: Corrosion-resistant housings that let plastic wheels be used in wet, washdown and chemical areas.
• Cast Iron: The housings and wheel centres behind the heaviest polyurethane and polyamide wheels, on the KAPPA series.
• Aluminium: Used under cast polyurethane on castors rated 250 kg to 800 kg, where a rigid metal centre lets the tread carry more.

Sizes & Types of Plastic Castors Available

Plastic castors in Accu’s range run from small plastic castors for apparatus up to heavy-duty transport castors, across the following sizes, fixings and ratings:

• Wheel Diameter (D): 14 mm to 200 mm.
• Wheel Width (T): 13 mm to 50 mm.
• Mounting Height (H): 17 mm to 245 mm.
• Approximate Load Capacity: 25 kg to 1,440 kg.
• Tread Hardness: 40 Shore D to 85 Shore D.
• Castor Type: Swivel Castor or Fixed Castor.
• 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.
• Thread Size: M10 x 25 to M12 x 30.

Solid polypropylene wheels are limited to castors from 38 mm to 80 mm rated 25 kg to 50 kg, and polyurethane on a polypropylene centre stops at 60 kg, while every rating of 500 kg or more comes from a polyamide or cast polyurethane wheel on an EN R43 plate. Threaded stem plastic castors use polyamide wheels from 50 mm to 100 mm and carry up to 120 kg. Most wheels are rated to between 60 °C and 80 °C, with heat-resistant thermoset versions up to 280 °C. Spare polyamide and polyurethane wheels, sold on their own in the Castors & Wheels range, fit many of these castors.

Where floors are uneven or a quiet, cushioned ride matters more than rolling effort, why not browse Accu’s Rubber Castors, whose softer treads absorb shocks and floor joints.

FAQ

Q: Are polypropylene castors good?

A: For light duties, yes. Solid polypropylene wheels in Accu’s range are rated from 25 kg to 50 kg on 38 mm to 80 mm castors, with wear resistance rated Very Good (4 of 5) and an operating range of -20 to 60 °C. They are light and hard-wearing, which suits furniture, light apparatus and small equipment carts. For heavier loads or wider temperature ranges, polyamide is the step up, carrying up to 1,440 kg and operating down to -40 °C on many sizes.

Q: Are nylon or polyurethane castors better?

A: It depends on the floor and the load. Nylon castors, with solid polyamide wheels at 75 Shore D, roll most easily and carry the highest loads, up to 1,440 kg, but they transmit more noise and vibration over joints and debris. Polyurethane castors have a slightly softer tread at 40 to 42 Shore D that grips better and is kinder to sealed or painted floors, and cast polyurethane on an aluminium or cast iron centre still carries up to 1,200 kg. On smooth concrete with heavy loads polyamide is usually the better choice, while polyurethane suits finished floors.

Q: What are the smallest plastic castors?

A: Accu’s smallest plastic castors are the compact COMPACTA models, with polyamide wheels from 14 mm to 45 mm on fixed castors carrying 25 kg to 40 kg at mounting heights of 17 mm to 48.5 mm, plus a single swivel castor with a 38 mm polypropylene wheel. Despite their size, the polyamide wheels at 65 to 75 Shore D still roll easily on hard floors. Small plastic castors like these suit instrument cases, drawers, small furniture and light apparatus where space beneath the equipment is tight.

Bespoke Plastic Castors Manufacture.

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