Products for bench top machinists | LittleMachineShop.com

Chuck Adapter, M39 x 4 Thread 4" Diameter

Chuck Adapter, M39 x 4 Thread 4" Diameter - Main image
$25.17 $39.95 In stock

This chuck adapter fits 9x20 lathes that have a M39x4 spindle nose thread. Use this adapter to mount 4" chucks such as LittleMachineShop.com PN 1698 4" 3-Jaw chuck or PN 1588 4" 4-Jaw chuck. There are no holes in this adapter so you can drill it for either a 3-jaw or 4-jaw chuck.

* These adapters require machining on the lathe on which they will be used. Instructions are included for final turning of the registration diameter on your lathe to ensure perfect concentricity.

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Customer Reviews (5.0 / 5 · 5 reviews)

Scarlett H. ★★★★★

Threaded right onto my 9x20 spindle with no wobble, and it holds my 4-jaw chuck perfectly true. Machining is clean and the fit is snug without being a struggle to tighten down.

Isabella ★★★★★

I was worried about slop on my 9x20 lathe's spindle, but this adapter seated with no wobble and the stainless steel face plate feels rock-solid.

Jacob ★★★★★

The threads engaged smoothly the first time with no wobble, and the adapter seats flush against the spindle face on my 9x20. Exactly what I needed to swap between my 3-jaw and 4-jaw chucks without fiddling.