The question mark is to invite anyone else who’s tried this to
contribute. I am no engraver, but a die customer of mine is, of
sorts, and wanted to find out if a finely-engraved texture cut into
the face of a pancake di e could be used to imprint the part.
The answer is yes, it works quite well on small parts with 20-25
tons. The part we tried is a small butterfly about 3/4" wide , with
crosshatch texture as background over it’s whole surface and deeper
vein lines spaced about 1/16" apart on average. I sawed the die out,
then he engraved it, then I heat treated it, using a stainless steel
foil envelope/wrap to prevent deterioration of the detail due to
oxidation.
It does not work to cut and emboss this way in one pressing. What
happens is that the metal stock prevents the die from closing any
further than the die thickness plus the stock thickness. Since the
engraving is recessed into the die’s face, this amount of die closing
does not engage the engraving with the cut part enough to allow any
metal from the part to move into the recessed engraving. It takes a
second pressing, after removing the stock that the part was cut from
and reloading the part into the die. This way the full force of the
press is directed to the part and the engraving.
This means that just about any texture or treatment one would care to
put into the die face will work with this method. Functionally, this
second= pressing is the same as coining, and what can be achieved
with 20 tons will be somewhat limited, generally to small parts.
Hammered textures would need to be applied before sawing,because
hammering will deform the shape of the cutting area if done after
sawing. It would probably work reasonably well to hammer a specific
area before sawing, as long as one is not planning on cutting thin
metals, 28g and thinner (?). Unless the hammer texture is all inside
the cutting area, places where the saw line runs into hammered area
will have their cutting effectiveness inhibited bcause of the
variations in tool thickness caused by hammering. Therefore cutting
thicker metals is suggested ; dies with less that perfect tightness
can cut thicker metal. This may not be a significant issue with fine
hammer texture, and it was not an issue with engraved lines that
crossed the edge of the cutting area.
Up until now, all of my die-altering for the purpose of forming
metal with pancake dies has been done by adding things above the flat
surface of the die; shot, wires, 3- dimensional forming modules, and
all of those work with one pressing. I’d actually be surprised that
someone has not tried the engraving idea before now. I know of one
person who engraves the outline of the design into the die plate as
a way of making it easier to saw the design accurately. Being no sort
of engraver, I am not inclined to try that method, but I imagine it
helps a lot with good engraving.
Dar Shelton