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View Full Version : Older Jacobs K4 Drill Key



Dale Lusby
03-21-2011, 04:53 PM
I picked up a Jacob's size 18 ball bearing drill chuck recently that didn't have the key. I also have an 18n but I assume the 18 is a little older as the gearing is a little different for the key. I contacted Jacob's and they said I would need a pre-1982 K4 key. I haven't been able to locate one and am hoping someone here might have one they would sell me. Shoot me a PM if you do.

CCWKen
03-21-2011, 07:15 PM
Is there supposed to be a difference in the early K4 keys? What changed, the pilot or the sleeve? I found a newer K3 at a flea market for my 1902 Jacobs No.3 chuck. Didn't know there were differences in the spec. :eek:

Dale Lusby
03-21-2011, 08:25 PM
The gearing on the sleeve is different. The tech at Jacobs told me I could replace the sleeve or find a pre-1982 key. He said it was still numbered k4. I believe the pin on the key still fits which I believe is 3/8". I have 5 k4 keys and none fit which is why I contacted Jacobs to begin with. I was surprised to find it the same number but different gearing.

PeteM
03-21-2011, 09:00 PM
This probably isn't your issue, but the chuck sleeve on an old chuck may have slipped or been pressed slightly out of position. Years ago when I was having trouble finding a key that fit, it just turned out the sleeve was displaced by 1/16" or so.

Dale Lusby
03-21-2011, 09:21 PM
This probably isn't your issue, but the chuck sleeve on an old chuck may have slipped or been pressed slightly out of position. Years ago when I was having trouble finding a key that fit, it just turned out the sleeve was displaced by 1/16" or so.

Thanks for mentioning that. I will double check so I'm not chasing my tail for no reason.

Dale Lusby
03-21-2011, 10:41 PM
As much as it pains me to admit you were correct. The sleeve had slipped off just enough to not allow the teeth to engage the key. I pressed it back into place and it works great. Thanks for the help. I wonder why the tech at Jacobs didn't know what he was talking about (not that I'm any better or helped). Oh well. Problem fixed.