A hollow diamond a pain in the tail, but too much more of one. You
just have to make two punches.
Looks like the link for my handout got a bit munged the last time
Easier way to find it is to go here:
That's an archive of a bunch of my student handouts. Click on the
chasing punches one, and away you go.
So step 1 is to make a diamond shaped punch that's pointed. Looks
sort of like the point of a nail, or a four sided pyramid.
Harden and temper it per the PDF.
Lock it point up in a vise.
Then take a blank chasing punch, heat the very end red hot, and
place it on the point of the pointed punch. (hang onto it with vise
grips) Make sure it's centered, then smack the end of the second
(hot) punch with a hammer.
The idea is to drive a diamond shaped depression into the center of
the hot punch.
Once you're happy with the size of the diamond shaped hole, stick
the hot punch onto your pumice pan, and bury it in more pumice.
That'll let it cool slowly.
Steel is bass-ackward of all the jewelry metals: to anneal it, you
cool it *slowly*.
Once it's cool, (hour or so) take a file and file the outside of the
formerly hot punch. The idea being to make a diamond shape that
echoes the profile of the diamond shaped hole you punched into it.
Leave the side walls as thick as you like for whatever design you're
after. Once you're happy with the profile, harden and temper it as
per the PDF.
To recap, the idea is to make a positive punch that is used to punch
a negative shape into the actual final punch, then file the outside
edges of the punch to echo the profile of the punched hole.
(Of course, you don't *have* to echo the punch-hole.....) You can
also do profiled male (first stage) punches.
Once upon a time, when dirt was young, and rocks were soft, I did a
lot of armor work. Had a fancy rose shaped punch that I used to
finish off the copper rivets holding the straps on. Did that by
making a steel 'rose' punch in positive, then used that to punch a
rose shaped depression into what became my finishing punch. Two step
punches like that are really handy things to be able to do. Don't
take much time to make, and pay off for *years* in terms of making
your stuff look fancier than other people's. For very little effort.