The drill chuck that fits in a lathe tailstock is in constant use in training and production workshops alike. Heavy use brings typical faults: the jaws move stiffly or jam, fine swarf packs inside, and rust appears on the thread and jaw guides from coolant residue.
A full service takes less than an hour and restores smooth action and a secure grip on the drill bits.
What you will need
Important: Switch off and isolate the lathe before removing the chuck. Always wear safety glasses when using compressed air: fine swarf flies off at high speed.
Step 1
Free the seized parts
Remove the chuck from the tailstock. Apply WD-40 Specialist Penetrant to the thread, jaws and body joints and give it a few minutes to work into the gaps. This lets you dismantle the chuck without pliers or excessive force, which easily damage the jaws.
Strip the chuck completely and lay the parts out in order on a clean surface.
Step 2
Clean the parts
Spray every part generously with WD-40 Multi-Use: it dissolves dirt, thickened grease and coolant residue. Work over all surfaces with the brush, especially the jaw threads and body slots, to clear out swarf.
Then blow all the parts through with compressed air to remove the remaining dirt and product and dry them.
Step 3
Inspect the condition
Check the jaws for chips and burrs, the thread for wear and the gripping edges for rounding. Remove small burrs carefully with a fine stone. Badly worn jaws are better replaced, as they will not centre the drill accurately.
Step 4
Lubricate the internals
Apply WD-40 Specialist Silicone to the jaws, their guides and the internal thread. It forms a thin, low-friction film that eases reassembly and gives a smooth slide and firm clamping. Unlike heavy grease, this film holds less fine swarf.
Step 5
Reassemble and protect the outside
Reassemble the chuck in reverse order and open and close the jaws fully with the key several times: the action should be smooth throughout. Finally treat the body with WD-40 Multi-Use and wipe off the excess. It cleans the surface further, restores the shine, stops squeaks and protects the metal from oxidation.
Tip: Wipe the chuck arbor and the quill taper before every fitting: even a fine chip on the taper spoils centring and damages the mating surfaces.
What next
In a busy workshop, give the chuck a full service every few months, and blow it out and treat it with WD-40 Multi-Use after every shift. Before a long idle period, especially in an unheated room, store the chuck lubricated and covered.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
More guides in «How to use».