Wood threads

R

rhram

Member
I recently worked on an antique that was made in around the early 1800's.  It had wooden threads on some parts.  The threads were in good shape.  Does anyone know how they made the threads back then?

Raul
 
Usually with a screw box and black smith made tap. Wood craft and beall sell modern equivalents. The woodwrights shop has an episode on making a screw box.

The modern versions have a 60 degree thread on them. I have never seen an antique tap, screwbox, or thread that wasn't 45 degrees. The modern makers all use metal cutting tools to make the large screws. This is incorrect and I would never purchase one. I make all my wood screws and use 45 degree cutters.
 
Up until the third quarter of the eighteenth-century, male threads were cut on the lathe using a hand-held thread chaser (a scraper with teeth filed in its end).

Even after the widespread manufacture and availability of thread boxes in the early nineteenth-century, chasers were still used for threading items like wooden door, drawer and shutter knobs as thread boxes are incapable of threading right up to shoulders.

I have several chasers – ranging from 3 TPI to 6 TPI – for threading the spigots on late seventeenth- and early eighteenth-century bun feet.
 
Thank you both for the information.  Mr. jack plane, would it be possible for you to send a photo of your thread chasers?

Thanks

Rhram
 
Robert Sorby make a set of thread cutting tools (http://www.robert-sorby.co.uk/threadcutsys.htm) as do Crown Tools (http://www.crownhandtools.ltd.uk/page74.html).

For a close up view, see John Lucas' home made chasers (http://www.woodworkingtalk.com/f6/home-made-thread-chasers-9295/).
 
That is a cool way to make a small thread chaser.  I want to make threads about 4 -m 6 TPI on a 2 1/2 inch diameter wood rod. 
 
Just curious why you would only want 6 TPI on a 2.5" rod. If for a bench vise I would want 2, 3 at most. Normally you want a fast movement for closing the vise. Easiest thing to do in that situation though is to Just buy one.

If for a different reason and your willing to use a smaller diameter, you can buy the beall tap at 5 tpi, or a cheap chinese screwbox at 6 TPI. Although both of these are 60 degree threads.

If neither of these would work for you let me know and I can make you one. I am limited to only 14" in length for the threaded portion. (I'm working on that though!)
 
Tim,
What is the factor limiting your length to 14 inches? I have made several vise screws and am working on wooden screw boxes and taps that will actually work.



There are ll kinds of people in the world. Those that can read Roman numerals and those that can't.
 
It's the setup I use for cutting threads, It was an experiment, one that worked out for once. But it allows me to cut any size thread and nut with any TPI. It can even do variable tpi, but I haven't figured out how to make a nut for that yet.

I plan to make a new setup thats more rigid and will allow for about 48" screws.

For some reason wooden screws and nuts have always fascinated me. I have had lots of wooden screws/nuts and the tools to make them go through my hands. And there are lots of different ways to make them.

Actually making the screws has always been pretty easy. It's making a nut that's hard. And making a matching nut that's even harder!
 
This English-made 4TPI thread chaser was with my turning tools and is the one I use most. I have a few other finer ones and one that's much coarser, but I can't put my hand on them right now.
 
I thank everyone for their help.  I am happy with the suggestion to use 4 TPI rather than 6 to 8.  I am in the process of starting a woodworking school in the Phoenix, Arizona area and I need eight woodworkers benches to start with.  I want to make 8 tail vices for the 8 benches and commercial screws are just to expensive for me at this time.  I plan to make these out of hard maple or beech and 2 1/2 inches in diameter.

Any other suggestions would be most welcome.

Raul
 
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