Cast Iron Castors.

What are Cast Iron Castors?

Cast iron castors, also known as forged iron castors, sit at the top of Accu’s Castors & Wheels range, with cast and forged iron housings built to carry from 500 kg to 1,440 kg per castor in demanding industrial settings. A reinforced, bulged fork and a 135 x 110 mm top plate, formed as solid iron rather than pressed from sheet, carry a 50 mm wide wheel in honey yellow polyurethane or black polyamide. That solid construction keeps the fork rigid under very heavy loads, so the wheel stays aligned and the castor keeps rolling and swivelling freely.

The standard depends on the wheel: castors with aluminium-centred wheels are listed under EN 12532, for industrial use at up to 4 km/h, while those with cast iron centres or extra heavy-duty polyamide fall under EN 12533, which covers industrial use at 4 km/h to 16 km/h. They suit heavy industry where loads are high and handling is rough, from press shops, die handling and machine relocation to heavy assembly lines, rail and aerospace workshops and transport frames for moulds, coils and large castings.

How Cast Iron Castors Work

A cast iron castor bolts to the frame through four 11 mm holes in an EN R43 top plate on 105 x 80 mm centres, with the load passing through the cast fork into a wheel running on precision ball bearings. The swivel versions turn on a double row ball race, or a taper roller bearing on the 1,440 kg castor, with an offset of 48 mm to 59 mm between the swivel axis and the axle so the wheel follows the frame’s movement. Grey cast iron is strong in compression and damps vibration well, and casting lets the housing be made in thick, solid sections, so the fork holds its shape under heavy loads and passes less vibration from floor joints into the frame. The wheel still sets the rating: polyurethane on an aluminium centre carries 500 kg to 800 kg, polyurethane on a cast iron centre 660 kg to 1,200 kg and extra heavy-duty polyamide 1,440 kg.

In an injection moulding plant, a mould transport frame moves a 3-tonne mould on a 400 kg frame between the mould store and the press. With only three castors reliably in contact, each one sees around 1,130 kg, which the 200 mm cast iron castor with a cast iron centred polyurethane wheel covers at 1,200 kg. At the push end, braked swivel castors steer the frame into position and hold it while the mould is lifted off; at the far end, a fixed pair keeps it tracking straight down the aisle. A pressed steel castor with an aluminium-centred wheel of the same size tops out at 800 kg, well short of what this frame needs.

Materials Cast Iron Castors Are Made From

Accu’s cast iron castors combine a cast iron housing with engineering-grade wheel materials, each chosen for very high loads and long, hard-wearing service:

• Cast Iron: Grey cast iron housings with a reinforced, bulged fork and a blue passivated finish rated Very Good (4 of 5) for corrosion resistance, plus grey cast iron wheel centres on the castors rated from 660 kg to 1,200 kg.
• Aluminium: The centre of the 500 kg to 800 kg wheels, with cast polyurethane bonded to it for a light but rigid wheel.
• Plastic - PUR: A premium cast polyurethane tread at 42 Shore D in honey yellow, rated Very Good (4 of 5) for wear and running performance and far kinder to floors than a bare metal wheel.
• Plastic - Nylon: An extra heavy-duty solid polyamide wheel at 75 Shore D in black, rated Excellent (5 of 5) for running performance and wear and carrying the range’s highest rating of 1,440 kg.

Sizes & Types of Cast Iron Castors Available

Accu’s range of cast iron castors is available in three wheel sizes, with swivel, braked and fixed versions for the heaviest handling jobs:

• Wheel Diameter (D): 125 mm to 200 mm.
• Wheel Width (T): 50 mm.
• Mounting Height (H): 170 mm to 245 mm.
• Approximate Load Capacity: 500 kg to 1,440 kg.
• Static Load Capacity: 1,000 kg to 2,400 kg.
• Castor Type: Swivel Castor or Fixed Castor.
• Brake Type: Total Lock Brake, Leading.
• Fixing Type: Rectangular Plate, EN R43, 137 x 105 mm.
• Plate Dimensions (AxB): 135 x 110 mm.
• Plate Fixing Hole Centres (ExG): 105 x 80 mm.
• Fixing Hole Diameter: 11 mm.

The 1,440 kg castor is only available at 125 mm, as a swivel castor with or without a brake, and there is no fixed version. The KAPPA PROTECT castors are unbraked swivel castors only, with a larger swivel radius of 142 mm to 190 mm, and every braked castor in the range uses a leading total lock brake. Worn wheels need not mean new castors, as most of these have a matching spare, including cast iron castor wheels with polyurethane treads, in the Castors & Wheels range.

For loads of 500 kg to 800 kg, why not browse the pressed steel ZETA castors in Accu’s Heavy-Duty Castors range instead, which carry the same ratings as a cast iron castor fitted with the same aluminium-centred wheel.

FAQ

Q: Are cast iron castors suitable for high temperatures?

A: Not these ones. Although a cast iron housing tolerates heat well, the wheels on these castors are polyurethane or polyamide, rated from -10 to 60 °C and from -30 to 80 °C respectively, so the wheel sets the limit. For high-temperature castors, Accu’s Stainless Steel Castors range includes heat-resistant versions with thermoset and damping rubber wheels rated up to 250 °C and 280 °C.

Q: Are cast iron castors stronger than pressed steel castors?

A: Not on rating alone. Fitted with the same aluminium-centred polyurethane wheel, the cast iron KAPPA and pressed steel ZETA castors carry identical ratings of 500 kg at 125 mm and 800 kg at 160 mm and 200 mm. The extra capacity comes from the wheels that only the cast iron housings take, with cast iron centred polyurethane wheels reaching 1,200 kg and the extra heavy-duty polyamide wheel 1,440 kg.

Q: Do cast iron castors have cast iron wheels?

A: Not in the traditional sense. Every castor in this range has a cast and forged iron housing, and nine of them also run on wheels with a grey cast iron centre, but every wheel has a polyurethane or polyamide tread rather than bare iron. That keeps them quieter and far kinder to floors than a solid cast iron wheel, which is hard, noisy and prone to marking concrete.

Q: How much weight can a cast iron castor carry?

A: It depends mainly on the wheel. With an aluminium-centred polyurethane wheel, a cast iron castor carries 500 kg at 125 mm and 800 kg at 160 mm and 200 mm; switching to a cast iron centred wheel raises that to 660 kg, 900 kg and 1,200 kg, while the 125 mm extra heavy-duty polyamide wheel reaches 1,440 kg. Static ratings, for loads that stand still rather than roll, run from 1,000 kg to 2,400 kg.

Q: Why is cast iron used for castor housings?

A: Cast iron can be cast into thick, complex shapes, so a fork and top plate can be formed as one solid section with material exactly where the loads concentrate, rather than folded from sheet. Grey cast iron is also strong in compression, hard-wearing and good at damping vibration, which suits castors carrying very heavy loads over rough floors.

Q: Will a cast iron castor rust?

A: Bare cast iron will rust if left wet, so the housings in this range are blue passivated and rated Very Good (4 of 5) for corrosion resistance, which suits most indoor industrial sites. For washdown areas, outdoor use or regular contact with water and chemicals, Accu’s Stainless Steel Castors are rated Excellent (5 of 5) for corrosion resistance and are the better choice for loads up to 500 kg.

Bespoke Cast Iron Castors Manufacture.

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