I am wondering if these dies are strong or fragile? Are they strong enough to strike huge numbers or are they likely to be damaged after only a small number of strikes?
Charles Larson in
Numismatic Forgery pp. 66-74 describes in detail the process by which transfer dies are created by either
plating or
casting. NOTE for the skim readers and those with low level comprehension skills: the casting process described by Larson is for the manufacture of
transfer dies NOT a
cast coin.
Transfer dies created from both methods are thin and fragile although the casting process results in a slightly more robust die.
To quote from Larson in discussion of dies created by plating from an authentic original
"Dies with applied nickel faces will not stand up to prolonged, repeated use, of course. But they will be perfectly adequate for striking a number of convincing specimens on well-annealed planchets - and the softer the metal being coined, the longer the forger may expect them to last."Larson also notes the shrinkage factor that is incurred with transfer dies created by the casting method,
"While the detail and proportions of such casts are excellent, the reader will recall that the greatest problem associated with casting - differential shrinkage - is accentuated if the object being cast is thin and flat [as occurs with the manufacture of a transfer die via the casting process]." So shrinkage of the fake coin design relative to the host coin image is a potential diagnostic of the
fakes. Through various steps and combinations of metal in the stages of manufacture of a transfer die by casting, the shrinkage factor can be minimized to the extant that as Larson notes
"About the only way to possibly detect it as a forgery would be to superimpose a magnified photograph of its surfaces over the image of a known coin."In considering the life of transfer dies made via the casting method Larson writes
"They have certain advantages over electroplate dies dies in that the are less time consuming to make, and more substantial and will normally last longer (for the production of a larger number of strikes), plus any number of dies can be made from a single set of molds - even if the original master coin has been sold or is otherwise no longer available. The crispness of the detail is only slightly less sharp than with electroplate dies...."So there you have it:
1) transfer dies from electroplate transfers are
good for a relative handful of examples on
average, but that doesn't stop the reproduction of multiple identical transfer dies using the electroplate process. Time consuming as this is it is best
applied to high value coins where the returns warrant the effort.
2) transfer dies manufactured through the casting process are more robust but
still only
good on
average for a few tens of examples. But multiple copies of the transfer dies are easily sourced from the original transfer. Speed of die production, loss of detail and shrinkage make casting process transfer dies the most economic option for lower value coins and bronze where the smaller margin is compensated by the higher volume of
fakes and the issues of loss of detail and image shrinkage are more difficult to discern.
Thus the number of fakes made is a function of the number of times the transfer dies were reproduced and put to use, rather than being determined by the life of a transfer die. Low transfer die life is readily compensated for by the manufacture of multiple copies of the transfer die set.
A corollary of Larson's expose is that transfer die life is extended by mechanical pressing in preference to hammer blow striking. This is due to the lower strain imposed on the thin die via a steady and gradual build up of
applied force as opposed to the higher deformation (strain) that arises from a
sharp heavy instantaneous blow. The latter tends to fracture the the thin transfer die after a few blows.
I commend Larson's book to anyone seriously interested in the subject. Without it you are guessing blind on the many and varied ways of manufacturing
fakes and the diagnostics of the different processes manifest on the end product (the fake coin).
Fake Coins and Notorious Fake Sellers
