Here's An Odd Drill Chuck For You...

[Holescreek]

Bought this in an antique mall this morning, Jacobs 16N 1/8"~5/8" capacity. Instead of the usual morse taper shank sticking out the back there was a 1/2-20 threaded rod in an adapter. I figured I'd pull the shaft out and free up the internal jacobs taper to mount on a lathe. Much to my surprise there was no jacobs taper, just a very odd .970"-14 internal thread. I downloaded the Jacobs catalog and it isn't listed so it must've been a custom for a specific machine builder.

 

[marcusp323]

I have one of those too. Came with an old SB 9" I had. Still don't know what I'll do with it, but seems I have a tough time getting rid of stuff, whatever THAT'S about
Mark

 

[ARKnack]

I would guess it came off some sort of drill. Heavy duty one of course. Marcus's, I to have a hard time tossing " valuable " stuff out.

 

[CluelessNewB]

1/2-20 was probably from a large portable drill but I believe it will also fit the headstock of some of the Craftsman 109 (AA) lathes and maybe some other smaller lathes also.

You can also purchase a 1/2-20 to Morse #2 adapter (Shars and Enco both list them)

 

[ch2co]

I've got one 'zaktly like it. Don't know where it came from and don't know what I'll end up doing with it, but it's a keeper!

CHuck the grumpy old guy

 

[randyjaco]

I had one like it on a SB 9". It was threaded to a hollow 2MT Arbor. Kind of a cheap extra small lathe chuck.
Randy

 

[Andre]

1/2-20 was probably from a large portable drill but I believe it will also fit the headstock of some of the Craftsman 109 (AA) lathes and maybe some other smaller lathes also.

You can also purchase a 1/2-20 to Morse #2 adapter (Shars and Enco both list them)

1/2-20 was also the thread size for the auxiliary spindle end of Craftsman radial arm saws. The chuck would mount to the end of the spindle opposite the blade (remove blade first) and used for drilling.

RA saws can also be used for, routing, planing, sanding, thickness sanding, moulding shaper, etc. not just a saw. A multi-function tool if you can find the accessories, or even make them.

 

[Holescreek]

I poked around on Ebay tonight and found MT3 (tanged) to 1/2"-20 thread adapters for around $7 and R8 to 1/2"-20 adapters for $6. I'll have to doctor up the .97-14 to 1/2-20 adapter that came with it to be useable again but at least I can use the chuck on either the lathes or Bridgeports.

 

[tertiaryjim]

I got a small one at a flea market for a couple bucks.
Made a threaded shank for it.
Chucked a dowel in it and used that to chuck it in the lathe to turn the shank true to the chucks grip.
Came out very nice.

 

[4GSR]

The 16N chuck generally comes with a 3 Jacobs taper for taper shank mounting.
Very good chance someone modified the chuck to fit a special threaded shank such as on a heavy duty drill motor or such.
Wouldn't surprise me if there is some speciality tools like Van Norman or Quickway built for the automotive rebuild industry that had this arrangement on some attachment. Who knows?
I wanted to modify a 20N chuck with a 1-1/2-8 thread to put on my 9" SBL, just can't justify doing it for what one cost today!