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Crude Blanking


G’day: “Once more into the breach, dear friends…” I very
often want thin sterling discs of various small diameters up to
a maximum of 1/2". So I make a very simple die thus: Get a piece
of steel rod around an inch dia., 1" long and put a centrepunch
mark in one end so that it when you drill the hole endwise
through it, the edge of the hole will be about 1/8" from the edge
of the steel. Hold it in a drill vice and use a bench pedestal
drill, not a free hand drilling machine. The first drill you use
should be 1/32" smaller than the diameter required. The second
drill should be 1/64" smaller, and the final drill can rotate at
higher speed and you will take it slowly. Why all this? So that
the final diameter will be as correct as possible and that the
sides will be very smooth. Hold the little cylinder in a bench
vice with the part which has the narrowest amount of steel
uppermost. With a hacksaw cut a slot into the side of the
cylinder just past the hole. A short piece of silver steel rod
(I think it is called drill rod in America) precisely the same
diameter, has one end cut and smooth filed at right angles. To
use the gadget, insert a bit of thin metal sheet into the slot,
enter the rod into the hole, then give it an almighty bash with a
good hammer. You can poke out the metal disc after you have
removed the rod - you’ll need to clamp the die in the bench vice
and drag it out with heavy pliers! Using such a crude device, I
have made literally dozens of discs in 0.5mm sterling sheet of
diameters from 1/2" down to 1/8". Put a polish on the sheet and
the rod and you won’t need to do much work on them. Dome the end
of the rod and polish it, bash the thing out over a sheet of lead

  • and you won’t need doming dies. Carve a pattern on the rod end
    and harden and temper it and you’ve got little flowers, or stars,
    etc. Wish I could give you a sketch. But this crude die
    stamper does work witout hassles in the making. Hassle ME if it


   / /    John Burgess, 
  / /
 / //\    @John_Burgess2
/ / \ \

/ (___)


John, it’s a really simple approach to the problem. May I make a
couple of suggestions to make it work a bit easier?

First, before you saw the slot from the side to hold the sheet,
increase the size of the hole from what will become the backside
for a depth of about two thirds the length of the total. This
depth will still be below where the slot from the side will be
placed. What the relief does for you is to allow the disc to drop
free once it is into the larger area. This will also allow the
rod to be removed more easily, as the slight burr that is created
when the disc is sheared from the sheet tries to wrap itself
around the end of the rod. Since this burr is trapped between the
proverbial rock and a hard place, it makes the rod difficult to
remove. I utilize this increased relief diameter approach in
another application, that although for a different purpose can be
used to help visualize John’s method. Take a look in the “Learn"
section of my web page under “Forming hemi-spherical beads”. If
the slot were sawed in the 1/8” tall forming area, you would
have John’s die. You would of course increase the length to
provide better registration.

Second, if you were to use a bit of lubrication on the punch, it
would make the removal easier.

Take care
Lee Marshall
Bonny Doon Engineering