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WTB: Brass Jaws for Jacobs no 100 chuck (U100)


Cast Iron
Apr 6, 2007
Ottawa, Canada
The no100 is like a Jacobs drill chuck that's fitted with brass jaws.

The jaws on my no. 100are pretty much shot, so I'd like to buy a replacement set. I believe the kit is known as a Jacobs U100.
... Gregg
I don't know where you can buy a set of brass jaws. I was always told that brass was a pretty slippery material for vise or chuck jaws. Is there a special application for brass-jawed chucks?
In this case. slippery is desired.

The Jacobs 100 chuck is designed to be used as a tailstock chuck for turning armatures, where the shaft slips inside the chuck as the headstock chuck rotates the armature assembly.
As awander says, the lack of friction is the whole point of the Jacobs No. 100 chuck, which is used to support the commutator end of an armature during machining.

There's misinformation about this chuck on YouTube, with a post where the presenter raves about how lucky he was to get a No. 100 tossed in with a machine he bought. He goes on talking about how well it works while plunging a twist drill into some work. I wonder how he got it to hold the bit tightly enough ...
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Thanks Seaman. I'm in Canada so I wrote to the seller to check on shipping. Turns out he will not accept bids from outside of the USA.

Thanks again,
.. Gregg