Cutting threads in wood

I've seen a few people making shift knobs and such out of wood. I think that's pretty cool and now I have most of the tools to do it. I'm just a little confused about threading.

Just get a metal insert or a helicoil set or similar, or can I actually use a tap on wood to thread it?

You need these.

Lowes carries them. They thread into the wood with a little epoxy.

Those fancy inserts or press a nut of some sort into a counterbore in the wood

Thanks Toyman. I'll have to hunt for them when I go electrical shopping this weekend.

you can also, if you wanna totally DIY/rig it, drill out the bottom of your shift knob about 1.75X the size you need, fill that hole with JB weld (which advertises its tap-ability), and drill/tap the hole you need.

-J0N

Yes, you can thread wood, but the insert is a better idea.

I agree, the inserts are a better idea.

Tee nuts are also an option if you have access to the backside of the panel. They hammer in, but I like to put a little epoxy under the flange first.

Edit: sorry... shift knob. Can't really use a tee nut

The main issue with easily available options is the thread pitch/count. Shift levers are usually a finer thread. The custom wood knobs I've seen typically have an aluminum insert that is drilled and tapped for the specific lever application.

That said, the brass insert might work if you can get one that's a bit too small and then drill out the existing threads and re-tap for the thread required.

Or just tap a metal tube and epoxy that into the wood. Basically the same thing everyone else is saying.

I would personally look to take apart a stock shift knob and get the innards and epoxy them into the new knob.

If it were a different application, there are a few dense hardwoods that wouldn't be too bad at holding even a fairly fine pitch screw. But again, I wouldn't trust it for a shift knob.

For custom knobs I've done both the insert (look up at specialty hardware stores for correct thread), and pressed and epoxied hex nuts.

another option is to drill out a hole the size of the nut or tapped tube needed, glue it in, then fill the hole behind it with a pre-center-drilled and appropriate depth wood plug.

I've made 2 wood shift knobs.....

1st one: Grecian Bryar root, my block was originally destined as a smoking pipe! On that one I drilled out to 1/2" and then using a small chisel I added the flats of a nut so I could "drop" a nut in - it was epoxied in

2nd one: Brazilian Cherry. This one was made to mimic the Nardi wood shift knob, and I used a an epoxied thread sert.

I picked a slightly different approach, for now. It's important to note that this is a procrastination project, so it could take a while to get off the ground.

I was a little pressed for time and cash at Depot picking up my electrical stuff, and stumbled across a 3ft length of 5/8" round steel bar. Large enough diameter for fitting on the miata shifter and anything else really. The portaband and drill press should make the length and hole size easy enough, although it's definitely not the easiest way to do it.

Thanks for all the help

Shift knobs are better heavy than light. Wood would be my last choice. Bismuth probably first.