How To Tell The Age of Jacobs Super Chucks

[JoeLee]

I have several Jacobs ball bearing chucks, 8 1/2N to 18N. I've noticed slight manufacturing differences in some of them, mostly visual stuff.
Some examples would be the way the lettering is imprinted around the top of the sleeve. Some of them look crisp and clean like they were imprinted or rolled into the sleeve. Some others look like they lettering is cast into the sleeve and the lettering is painted black. Maybe at one point Jacobs started casting the sleeves.

Also the lettering around the nose of the chuck where the key holes are. I've noticed changes in the lettering style and positions, the size or model of the chuck, drill bit size from x to x. Taper size and some also have a service kit number stamped in there.

I also have an older 16N, probably older than any of my other chucks as it came in the old style green box. On that one the key holes are drilled all the way through as opposed to the newer ones where the holes are blind. I don't like the open or through holes because it allows all kinds of small chips to get into the jaw area. Jacobs must have realized that at one point and changed the design.

Forget the new made in China ones........... The lettering is either painted or laser etched in black.

Can anyone put a approximate time frame to any of these changes ??

JL.................

[DR]

The only thought I've given to age of Jacobs chucks is that the cosmetic details you mention are obvious on later models. Whether the actual workings of the chuck have been compromised in the interest of cost savings I can't say for sure, but I suspect they may be.

[JoeLee]

I'm sure they cut corners internally as well. I can see on some of my chucks that when the jaws are fully retracted and you can get a partial look up inside, the internal walls where the jaws slide aren't finished nearly as clean as on some of the older chucks. The top sides are now just turned where as my older ones are nicely ground.

JL.....................

[rkepler]

The things I key on is the acid etched name/model - they started doing that with the move to China and I've always used it as a 'stay away' sign.

[Glug]

This is a timely thread. I've had that same question.

I was at a great estate sale over Memorial Day weekend. There was a big Jacobs 18N super chuck. Unlike the super chucks I am familiar with, it had straight sides. I'd never seen one like that. As JoeLee mentions, the key holes are drilled all the way through. It seemed lightly used, but a bit sticky- maybe due to sawdust, though you can't be sure. It also had a bit of backlash.

I passed on it at $30 and hoped someone would buy it. Jacobs rebuild kits are expensive, and may not even be available for older chucks.

They had the sale again around the 4th of July weekend.. Still Lots of tools, and now some great old books. The chuck was still there. I didn't dicker - I said I was willing to go $10 and they agreed.

Blowing it out hasn't really improved it, so it looks like it will go in the R&R pile. While I'm in there, I guess I'll see if there is room to close those keyholes with epoxy.

[JoeLee]

The things I key on is the acid etched name/model - they started doing that with the move to China and I've always used it as a 'stay away' sign.

Acid etched, that's it. Without actually seeing one in hand I figured they were laser etched. Acid etching can look real bad. I have a set of L&I reamers that are acid etched and on the smaller ones you can't read the runny looking smaller sizes. Looks like a marker when it bleeds out on wood.

JL................

[JoeLee]

This is a timely thread. I've had that same question.

I was at a great estate sale over Memorial Day weekend. There was a big Jacobs 18N super chuck. Unlike the super chucks I am familiar with, it had straight sides. I'd never seen one like that. As JoeLee mentions, the key holes are drilled all the way through. It seemed lightly used, but a bit sticky- maybe due to sawdust, though you can't be sure. It also had a bit of backlash.

I passed on it at $30 and hoped someone would buy it. Jacobs rebuild kits are expensive, and may not even be available for older chucks.

They had the sale again around the 4th of July weekend.. Still Lots of tools, and now some great old books. The chuck was still there. I didn't dicker - I said I was willing to go $10 and they agreed.

Blowing it out hasn't really improved it, so it looks like it will go in the R&R pile. While I'm in there, I guess I'll see if there is room to close those keyholes with epoxy.

They all have straight segmented sides unless it's a plain bearing chuck, they look a little different.
If the key holes are drilled straight through it's old, not sure of the year. That's what I was trying to find out when I started this thread.
My 16N was brand new, and it was sticky too. Probably from sitting around for so many years without use. It was NOS.
I thought about plugging the holes too, but after measuring the depth and the length of the peg on the key I came to the conclusion that I would have to shorten the key peg and on a big chuck like that you don't want a shallow hole or the key may pop out when your tightening it. If your using epoxy your going to have to seal off the bottom of the hole or it'll run down into the chuck.
I use mine on my lathe so only one hole is facing upward.

JL....................