The Handsome & Co Educational Taster: How To Make Hand Screw Clamps (with spoilers)
There’s something magical about threading timber with a thread box and tap, like a well-executed illusion, the dowel is transformed effortlessly and instantaneously with a simple (maybe even flamboyant) series of turns of the wrist.
As easy as sharpening a pencil, the thread emerges from within the thread box like a rabbit from a top hat. It is an impressive trick, outwardly complex, but only requires a small amount of preparation and most importantly, a set of specialist tools; a tap and die suitable for timber, that do all the work for you.
The similarities don’t stop there, like a magic trick, once you know the secret, the magic is lost and the illusion is no longer impressive, instead it is much more like the plain old woodworking we all know and love.
So…. if you wish to stay green and maintain your youthful view of wooden threads, I caution you to stop reading here as the following text is comparable to finding out magic is as fake as Santa Claus.
You’ve made it this far and so I assume you want some tips and maybe even a little dispelling:
Preparation is the key to successful woodworking practice, and threading and tapping timber by hand is no exception. So avoid frustration:
- Turn the dowel that you hope to thread a little bit undersized. Life will be so much easier because the major diameter of the post won’t hit the bottom of the threaded hole.
- Use straight grain hardwood dowels, these work the best.
- Make sure the dowel is the correct/suitable size to suit the threadbox, also check that the dowel is round, not oval.
- Lubricate the parts to be threaded in Linseed Oil (or Tung Oil). This is the most important step, regardless of how sharp the cutter is inside your thread box, the better the lubrication the easier it will be to cut and the cleaner the resultant threads will be. Some harder timber types may require you to soak the part (dowel) you wish to thread from anywhere from a few minutes to a few days.
Making Hand Screw Clamps is an easy project and requires almost no skill, just a little preparation and the right tools.
- 2 x lengths of 19mm hardwood dowel @ 360mm in length.
- 2 x pieces of hardwood timber measuring approx. 35mm x 35mm @ 220mm in length.
- 1 x 3/8 (19mm) Thread box with accompanying tap.
- 1 x 19mm forstner drill bit
- 1 x 16mm forstner drill bit.
- Linseed oil and a container to put it in.
- In addition to these main specialist woodworking tools, you’ll also need a sharp pencil and a ruler.
Step 1 – We’ve milled our 19mm dowel from octagon section, leaving 120mm of octagon section for the handle; this is an optional and complimentary component to function. For simpler version source 19mm hardwood dowel, cut to length and submerge in linseed oil to soak for 30 minutes minimum.
Step 2 – In one piece of the jaw stock drill two 16mm holes all the way through using a drill press, laid out as per the diagram. In the other remaining piece of jaw stock drill two 19mm holes, one of which goes all the way through and the other only ¾ of the way through, again, lay out as per the diagram.
Step 3 – Remove the dowel from the oil, wiping off any excess oil with a rag. Secure in a vice and thread 240mm of the dowel, leaving 120mm for a handle. Once the thread has been cut, back out and remove the thread box, do not reapply the thread box as this will cross-thread and ruin your threaded section.
Step 4 – Tap the 16mm holes, ensuring that you cut all the way through before backing out. Linseed oil can be used on the cutter to assist the tapping process.
Step 5 – (Optional) Cut a taper to the nose and chin of the jaw stock of your clamp. Chamfer, sand and apply a finish of your choice to all parts. I’ve listed this step as optional, as these things are decorative and do not directly affect the functionality of the clamp
Step 6 – Assemble the clamp and you’re done. Simple right?