3326 Chuck, Set Screw Swap ?

[nuhobby]

Hi,

I have stumbled onto a very nice old Jacobs 3326 drill chuck. Only slight irritation is that the set-screw takes a 3/16 hex-tool rather than the 'universal' 5/32 hex-tool. Has anyone ever found a set-screw to put a 5/32 tool hex screw in the 3326 chuck?

Thanks,
Chris

[JPG]

Not since they became standardized. They at one time existed.

[rpd]

Hi,

I have stumbled onto a very nice old Jacobs 3326 drill chuck. Only slight irritation is that the set-screw takes a 3/16 hex-tool rather than the 'universal' 5/32 hex-tool. Has anyone ever found a set-screw to put a 5/32 tool hex screw in the 3326 chuck?

Thanks,
Chris

That chuck shipped with a 10ER.

10ER's use a total of four different hex key sizes.

These are the four chucks I own.

drill chucks.jpg (319.94 KiB) Viewed 5264 times

from the left

1 & 2 - came with 10ER's - marked Jacobs 3326 - 3/16 hex key - K32 chuck key

3 - came with Mark 5 (greenie) - marked Jacobs Multi-Craft MC-3326 - 5/32 hex key - K32 chuck key

4 - purchased on EBay - marked Jacobs Multi-Craft MC8K26 - 5/32 hex key - KK chuck key

[cham-ed]

The 3326 should be the best of the bunch at least originally. It is the top of the line. The later ones were more of looser design.

[chapmanruss]

Ron's picture above shows two of the Jacobs 3326 Chuck which started out as a chuck for the Model 10E & 10ER and replaced the Jacobs 33B Chuck on an adapter. When the Mark 5 was being introduced the plan was for all possible set screws be changed to the 5/32" Allen Wrench size. The first Jacobs 3326 Chucks sent out with the Mark 5 still had the 3/8" threaded hole the same as ones for the Model 10's using a 3/16" Allen Wrench but they used a special size 3/8" set screw that uses a 5/32" Allen Wrench. Eventually the hole was drilled & tapped at 5/16" to take a standard 5/32" Allen Wrench size set screw. So to answer your question Chris, yes the was a 3/8" set screw that used a 5/32" Allen Wrench.

Below is the three Jacobs 3326 Chucks used for the Shopsmiths.

3326 Chucks.jpg (355.12 KiB) Viewed 5157 times

Note the differences in the set screws.

The other two chucks in Ron's picture are the Jacobs Multi-Craft Chucks supplied by Shopsmith Inc. with the Mark V's for a time.

[nuhobby]

Thanks all for the info!

Standardization of fasteners and threads is interesting... I like to tell my brothers how the Stanley-plane thread sizes pre-date the SAE standards.

Chris