I have a Nova G3 chuck which by default comes with the 50 MM jaws. 50 MM is just a bit less than 2 inches but fully contracted will not fit into a 2" hole. I bought the 31 MM jaws and they will not expand enough to make contact in a 2" hole. Amazon says the JS-SP45 has an expanding grip of 2.04 to 2.83 even though 45 MM is 1.77". I read that as too big for a 2" hole. Anyone have the JS-SP45 and know what size holes it will fit into? Thanks

  • Can’t help, except to say that if you buy online, understand return policies (including return shipping expense). Commented Jan 25 at 1:22
  • "I bought the 31 MM jaws and they will not expand enough to make contact in a 2" hole." How far off? Can you pack them out slightly? If that sounds dodgy (although it's done in engineering circles all the time) does the hole have to be 2" exactly? I would have thought there was some wiggle room on that front, unless the size is set by a Forstner bit or something that you don't want to modify.
    – Graphus
    Commented Jan 25 at 8:05
  • I am making the 2" hole with a Forstner bit as you guessed but the size is very appropriate for what I am doing and isn't quite right smaller or bigger. But thanks. Commented Jan 27 at 18:29

2 Answers 2


There should be a solution here which won't require purchasing another chuck, based on common practices in lathe work.

The first thing I thought of, as mentioned in the Comments, was just packing out the jaws individually (as is routinely done with metalworking lathes). But I think you can go one up from that.

Simply turn a flat ring from wood with a suitably smaller inner diameter and a 2" OD. Saw through the ring at one point — you deliberately want to lose wood to the kerf here — and this can be slipped into your 2" recess, and will then grip tightly once the jaws of the smaller chuck are expanded. A close-grained hard wood like sugar maple might be ideal here but experiment and see.

Alternatively, turn a multi-radius spindle with a very slight taper on the 2" end and at the opposite end a diameter that one of your existing chucks can comfortably grip. Jamming the turning on should hold sufficiently for any turning techniques within reason, based on similar techniques used in both Russian and Japanese bowl turning, and the friction hold of cup centres.

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    Wow, just when you think you are getting a handle on things you run into a whole new block of knowledge. This packing concept is quite cool and obviously I had never thought of it. It will be stored for future use as my turning skills mature. Thanks! Commented Jan 27 at 18:27
  • Welcome! Glad to add on of those "Aha!" titbits to your block of knowledge, I personally love it when those happen. This is why I now watch a wider range of YouTube channels than I used to (for years I used to exclusively watch woodworking, and primarily hand-tool woodworking, channels). It is surprising what you can see in other areas that has potential application, or at least can provide inspiration for another way to do something. Cheers! :-)
    – Graphus
    Commented Jan 29 at 6:42

I really appreciate the input but the pretty thin packing ring may be beyond my skill level at this time and the hole indeed needs to be 2". I indeed have all my receipts and returned the 31 mm and 45 mm jaw sets and got the Nova 6019 35 mm jaws which worked just fine expanding into the 2" hole. I will also quit relying on Amazon's description of capabilities and alwasy refer to the Nova website where specifications are complete, accurate and most of all consistent. Thanks guys!

  • Welcome to Woodworking, please take the tour. You'll note that posting "thanks" as an answer isn't the way we roll here. Instead click the up-arrow for every answer that helped you and the check mark for the one that helped you the most. Unless, of course, your answer was totally different from any of the other answers..
    – FreeMan
    Commented Feb 7 at 16:57

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