Charles

Or is this a drill chuck (which normally would be expected to be

Take it apart and grease it inside.

Try a lithium grease inside. Is this the standard scroll plate type of chuck? Where is it slipping? Is the gear on the OD of the scroll plate pressed on, or machined as part of the plate? Are the bevel gears that the key fits one-piece or two-piece? Find out where it is slipping and perhaps you can fix it by pining, or welds, or whatever. (Or can perhaps get a replacement part from the maker?)

If a Jacobs style drill chuck (which might fit the size you specified), there is a ring with internal threads which is a press fit into the outer body shell of the chuck with the gear teeth to mate with the chuck key on the end. That ring is typically machined from cast iron, then broken at two intentional weak points 180 degrees apart so they can be put on over the matching threads in the jaws. The press fit into the outer shell holds it together. If *that* is slipping, I'm not quite sure what the best way to fix it would be. Perhaps a thin braze layer on the OD then machined back to a proper press fit into the shell? Or buy a rebuild kit which includes new jaws and ring. (Of course, if the ID of the shell is worn larger, the rebuild kit will probably not do much good.

Good Luck, DoN.

On Mon, 15 Sep 2008 18:57:50 GMT, with neither quill nor qualm, Jerry Wass quickly quoth:

I returned a set of knockout punches to HF for that problem, but I could feel it before I even tried using them. The screw was loose as a goose in the threaded die and stripped clean away when torqued to about 20 ft/lbs. I returned it for credit, the first tool in a long time I've had to return (maybe 1:150.)

-- Guard well within yourself that treasure, kindness. Know how to give without hesitation, how to lose without regret, how to acquire without meanness. -- George Sand