I can offer some of my experience about this subject via the
pancake/RT blanking die route.
("Red " has kindly but misleadingly overstated my abilities in the
diemaking area. I appreciate this being posted so that this community
can be more precisely informed about it’s resources. )
I am NOT a tool & die maker in the traditional machine shop sense.
There are a million things these people can do that I don’t go near.
That being said, I can do a quite lot in the low to medium-tech area
of cutting and forming with pancake dies and hydraulic presses.
Regarding washers…this problem is documented at Lee Marhall’s
site with that I formulated and he edited and presented .
The ‘donut hole die’ (using RT/ pancake technique) as I call it is a
world of trouble unto itself .Though it can be made to work
serviceably, it’s debatable whether it’s worth the trouble , and just
isn’t in some cases. Centering the hole is very awkward and next to
impossible for any but the simplest designs. The real drawback with
this approach is of course that the part becomes trapped between the 2
dieplates that comprise the die , and so must be extracted with a
specially made stripper plate. The method can be viable and
economical if a lot of parts are needed, but certainly there are less
expensive ways to go, as these are way more costly than plain pancake
I don’t have many fond memories of the kind of hole punches that
several people here describe, but apparently they can be tamed . I
probably just had a lower quality one . I often refer people to Roper
Whitney Co. and their line of hand held and benchtop presses ,
stock and custom made punch & die sets. Oh, and listening to folks