Swap worn or broken castors on a chair, desk or unit so it rolls smoothly and stands level again.
RC-01Work out what castor type you haveTurn the chair or unit over and look at how each castor attaches. It will be a plug-in stem that pushes into a hollow leg, a threaded screw-in stem, or a flat plate screwed to the base with several small screws. Measure the stem diameter or plate size with a tape measure, and take a photo for reference.
RC-02Buy a matching replacement setMatch the stem type and diameter, or the plate size and screw hole spacing. Check the weight rating suits the job — an office chair castor needs at least 50kg rating. Buy a full matching set of 4 or 5 so the item sits level, not just one replacement.
RC-03Prepare your workspaceClear a flat area and lay down an old sheet or towel to protect the floor and catch dust. Get your tools within reach before you start so you don't leave the item balanced upside down while you search for a screwdriver.
RC-04Turn the item upside downRest the chair or unit upside down on the sheet, resting on its seat or top so the legs point up. If it's heavy or awkward, get someone to help you tip it safely. Check nothing loose can fall out or scratch a nearby surface.
RC-05Remove the old castorsPull plug-in stems straight out — grip with pliers and wriggle if they're stiff or rusted in place. Unscrew screw-in stems anticlockwise by hand or with pliers on the stem. Undo plate castors by removing all the small screws with a screwdriver.
RC-06Clean and check the fixing pointWipe out old dust, grit or dried glue from the hollow leg or plate area with a dry cloth. Check the leg isn't cracked or split around the socket — a split leg needs repair or a wood glue fix before a new castor will hold properly.
RC-07Fit the new castorsPush plug-in stems in firmly and squarely until they seat with a click — tap gently with a mallet through a folded cloth if it's stiff, never hit the plastic wheel directly. Screw in screw-type stems clockwise until snug, not overtightened. For plate castors, drive all the screws in evenly, corner to corner, so the plate sits flat.
RC-08Turn it back over, test and tidy upStand the item upright and roll it back and forth to check every castor turns freely and sits level. Look underneath once more to check nothing is loose. Pack away tools and put the old castors in general waste unless your council recycles metal parts separately.
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