bob wrote:
I want to make a wood screw for a vise(2in. dia). I have tried using
dried and green oak and 3 tpi. The threads for the nut cut very
nicely
but the outside threads are a mess. Lots of chipping and tearing. Is
it
the wood, the tool grind ,or me? I have also tried cherry and it was
worse than oak. My brother ground the tool for the inside threads and
I
ground the tool for outside and am a relative clutz so I hope it is
just the grind.
Anyone with experience doing this?
Thanks,
Bob


Oak is probably going to be a non-starter. You need a close-grained,
tough wood, like hickory, maple or ash. They make threadboxes for
doing the male threads, the thread isn't much like a metal thread.
Several woodworking books I've seen tell you to shape the threadbox
cutters and make the threadbox itself. Or you can go to some of the
specialty places on the internet and buy them and the matching taps.
I've used threadboxes on 1" stock, they work OK with the right wood.

Another method is to use a router jig, this company,
http://www.bealltool.com/, makes jigs. If you're tooled up, you could
probably make one yourself. The owner also has a book out on wood
threading.

See http://www.woodshopdemos.com/beall1.htm for a how-to with the jig.
Stan