Toolmaking - Stud Clamps

I love making little tools. I've been meaning to do this one for a while but I finally got round to it as I needed to do some work on an M4 threaded assembly. A few years ago I did an engineering operations qualification at night school and I had to make numerous different tools/jobs to finer and finer tolerances, one of the jobs was the larger stud clamp in this picture. Basically you cut and tap some hole for a range of threads (in the case of the larger one M6 to M12) and then cruelly are made to hand cut all the way through your work piece ( a test of nerve and skill on the course as it needed to conform to the specified tolerances!). The resulting object is very useful for a few different tasks... Primarily if you thread a bolt or threaded bar though a hole and then clamp it in a vice the cut section closes tightly around the threaded object and allows you to work on it/cut it etc with it held firmly and without any damage to the object. A secondary use is if you have a threaded stud stuck into something with little to grip onto to remove it (imagine a cylinder head stud for example) you can thread on the stud clamp and then clamp the cut end with a pair of mole grips and it creates a hug wrench to remove the stuck stud with.

So it tends to be that M6 is the larger end of stuff I work on and therefore I decided to make a smaller version for the sizes M2, M3, M4 and M5, I used a little piece of en1a and again did the cut with a hacksaw... which is on the limit of being too wide for the M2 section but just left enough thread to form a precise clamp! I also chucked some drill bit gauge holes into the piece for the drill sizes needed to drill a hole to tap for M2,3,4.

Its not to as high a standard as the larger one in many ways, but is functional and I do get a great sense of satisfaction out of making things like this... with a bit of care this tool should see reasonably regular use in my shop for the rest of my making days!