Finish the jaws with a little hand fitting. Fit a fine tooth straight edged file
and using the safe edge, into a vice and slide the jaw backward and forward along
this. I find this much easier than placing the workpiece in the vice and moving the
file. Remove burs, etc. stamp the jaws 1, 2 and 3 ensuring that this is done on the
correct jaws, and the jaws are finished. If you make a second set it is essential
that they are kept in sets. In this case mark the jaws 1A, 2A and 3A and the second
set marked 1B, 2B and 3B.
If you attempt the task I do hope you find it not that difficult. You will though
have to keep your mind on the job ensuring that you machine the required radius with
the correct offset, etc., etc. Photograph 5 shows the finished result and that I
made a second set that were adapted by fitting hexagonal jaws.
If you have some low profile clamps you can both thickness the jaws and make the
grooves by machining them as I did, Photograph 6 and 7. This bypasses any error in
the vice such as jaw lift and the inner surface not being parallel with the vice's
base, etc. See page elsewhere on the site for details of low profile clamps that
can be made in the home workshop.
Close examination of the two Photograph shows that I added an additional support
when machining the groves. The low profile clamp that I used is capable of considerable
clamping force and I was concerned that just possibly it may move the fixed jaw with
disastrous results. I think I was being overcautious but it is better to be safe
than sorry in such critical operations.
I have not yet mentioned the subject of the grade of material to be used. In view
of the amount of machining to be done, especially the teeth, a free cutting steel
will be very beneficial. Unfortunately, 230M07 (En 1A), whilst made in rectangular
sizes they are not easy to obtain. Rather easier is square bar in a reasonably wide
range of sizes. I used 32mm square that I then split in two loosing about 1mm with
the saw blade. This gave me two pieces nominally 15.5mm wide which had to be reduced
to 15mm. I would also advise that it would be very worthwhile purchasing a new cutter
to machine the teeth with, as it will cut much better than one that has been much
I do not see this project as a means of saving money, though if you make more than
one set it just maybe, but as a way of acquiring some soft jaws for a chuck for which
they are no longer available. They would also make a useful project for the workshop
owner wishing to take on something different from the usual turning and milling activity.