Correct installation is important to ensure castors swivel freely, carry the intended load and provide reliable service. Castors should be mounted vertically. If a castor is not mounted vertically, it may track to one side instead of swiveling correctly.

Plate-Mounted Castors

Heavy-duty trolleys generally require industrial plate mounted castors. The base of the trolley or equipment must be strong enough to withstand the load being carried.

Never mount a plate castor using only three bolts. All mounting holes should be securely fastened, and the mounting base should be strong enough to support the intended load. Do not compromise the strength of the mounting base when fitting heavy-duty castors.

Up to approximately 8 mm of adjustment can be achieved using washers, or with a suitable piece of tube tightly fitted between the trolley leg and castor. The adjustment piece must not be allowed to move or float.

Tighten tubular fittings firmly, but do not over-tighten them.

Checking Castor Fittings

Castors should be checked after the first 3 months of use and annually thereafter. We recommend checking that the fittings remain secure without being excessively tightened.

As a general guide, we recommend "3 finger" tightness — approximately the amount of torque that can be applied to a standard spanner using your three middle fingers. Always follow the manufacturer's specifications where they are available.

Tube Fittings

Medium-duty castors are often fitted into tubular trolley legs. As with plate-mounted castors, it is important that the trolley legs remain vertical so the castors can swivel correctly.

We recommend that the leg should not extend more than 125 mm below the nearest supporting point. Except for the lightest applications, the tube should be at least 1.4 mm thick. Thinner tube gauges are more likely to split under load.

If you want to use lighter-gauge tubing elsewhere on the trolley, insert a sleeve for at least 150 mm where the castor is mounted. This provides additional strength around the castor fitting.

Round and Square Tube Fittings

Never fit a round expanding adaptor into a square tube. When a trolley hits a bump, the square tube can deform or elongate, potentially allowing the castor to loosen or fall out.

Use the correct castor fitting for the shape and size of the tube. SWC supplies square fittings for applications requiring them.

If a round fitting must be installed into square tubing, we recommend welding a round-tube sleeve into the square tube first. The smallest fitting requires a 3/4 inch internal diameter.

Directional Lock and Solid Stem Castors

When using Directional Lock (DL) castors, a solid swivel stem is preferred. The stem can be welded or bolted into position. Screwed fittings can potentially become misaligned during use.

For the best performance with larger 175 mm and 200 mm castors, we recommend using solid stems.

Fitting Expanding Stem Castors

When fitting an expanding stem castor, make sure the fitting is fully inserted into the tube before tightening.

1. Make sure the tube is firmly down onto the castor head rivet.

2. Check the inside of the tube and remove any burrs that could prevent the fitting from being inserted fully.

3. Check that any internal weld is not excessive and align it with one of the slots on the outside of the adaptor fitting.

4. Insert the fitting completely into the tube.

5. Apply some sideways pressure to help the fitting grip the inside of the tube.

6. Tighten the stem bolt firmly, but do not over-tighten it. Excessive tightening can make the castor difficult to remove later.

Tube fittings on expanding stem castors should be checked after the first 3 months of use and then annually. Make sure the tube fitting remains fully and firmly inserted into the tube and that the tightening nut remains secure without being over-tightened.

Greasing Castors

Regular lubrication can help extend the working life of a castor and keep it operating smoothly. Grease in the swivel head race and wheel bearing serves three main purposes:

• Helps prevent rusting of the balls and raceways
• Helps prevent galling
• Reduces noise

Only a relatively small amount of grease is required. Too much grease is unnecessary, can attract dust and dirt, and can make the castor messy. A liberal smear is generally sufficient.

If you only have a few castors to grease, grease can be applied with your finger and the excess wiped away with a rag. Alternatively, use a needle-tip grease gun.

Greasing Multiple Castors

If you have a large number of castors to maintain, the following procedure can make the job easier:

1. Turn the trolley upside down and remove the wheels.

2. Regrease the swivel head. If the castor has a grease nipple, apply grease through the nipple. Otherwise, use a needle-tip fitting on a grease gun. On heavier-duty castors, you may need to carefully lift the seal using a sharp-pointed screwdriver. Two full squirts are usually adequate, but make sure the grease reaches the centre so it can work down to the bottom race.

3. Check the axle bushing for wear. If it is not heavily worn, it can generally be reused. Replace it if excessive wear is present. Apply approximately a teaspoon of grease along the inside of the wheel bearing, working the grease into the rollers before reassembly.

4. Protect the wheel seal. Take care not to damage the lip seal when reinserting the axle bushing into roller-bearing wheels. Make sure the axle bushing is clean before inserting it.

5. Reassemble the wheel. Fit the wheel back into the castor and replace the washer where fitted. A small amount of Loctite High Assembly Strength solution on the axle thread can be used as an additional precaution where appropriate.

6. Use the correct grease. We recommend No. 2 bearing grease that is not sodium based.

Castor Maintenance

Correct installation and regular maintenance can significantly extend the working life of your castors. Regularly check mounting bolts, tube fittings, wheels, bearings and swivel mechanisms for signs of wear or loosening.

For demanding applications, see our range of heavy-duty castors, or browse our complete range of castors for different wheel materials, load capacities, mounting options and brake configurations.

If you are replacing existing castors and need help identifying the correct fitting, load capacity or wheel size, contact SWC and we can help you find the right option for your application.