Drill chuck capacity

I just noticed that on keyless chucks, the jaws spin when tightening and loosening the chuck and on keyed chucks the jaws never spin. It all makes more sense now. Probably old news to you experienced guys. I'm guessing that you don't want to use left hand drills in a keyless chuck either?
 
??? Never heard of the jaws spinning in a chuck. Could you clarify what you mean?
 
OK, let me see if I can explain. Install a keyless chuck on your tailstock. When you tighten or loosen the chuck, the jaws turn around with the chuck body. On a keyed chuck, the jaws remain stationary and just go in and out. You may need both in hand to notice the difference in how they work.

To confuse things even more I noticed that the keyless chuck on my Makita hand drill functions more like a keyed chuck with a fine thread and some sort of ratchet clicky mechanism.
 
Keyless chucks tighten with the load applied to them. A bit larger than its capacity will over tighten it to the point you need a pipe wrench to release it. Don't ask how I know.

Greg


I've had exactly the same thing happen with the 5/8" precision keyless in my DP. Whenever I use a large drill bit in steel, it locks up. I wrap
it with a strip of leather before applying the pipe wrench. :)
 
I've had exactly the same thing happen with the 5/8" precision keyless in my DP. Whenever I use a large drill bit in steel, it locks up. I wrap
it with a strip of leather before applying the pipe wrench. :)

Whenever?! You've done it more than once? How's the precision of that chuck now?
 
I think it's happened twice. First time I didn't know any better. Second time, I forgot the first... :)

The chuck's fine.
 
I just noticed that on keyless chucks, the jaws spin when tightening and loosening the chuck and on keyed chucks the jaws never spin. It all makes more sense now. Probably old news to you experienced guys. I'm guessing that you don't want to use left hand drills in a keyless chuck either?

OK, let me see if I can explain. Install a keyless chuck on your tailstock. When you tighten or loosen the chuck, the jaws turn around with the chuck body. On a keyed chuck, the jaws remain stationary and just go in and out. You may need both in hand to notice the difference in how they work.

It took me a few days to get out to the shop and check, but you are absolutely correct.
Funny, I had not noticed that before.

Thanks for posting!
-brino
 
I hadn't noticed it either. Yesterday, went to mount a dial indicator into the keyless chuck and yes it rotated as I tightened it.

Greg
 
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