In the process of creating working dies for the striking of an upcoming product release, we thought we would share a quick video of an essential step.
After having former US Mint Engraver Tom Rogers create reproduction sculpts of the famous Gobrecht Dollar main devices, these sculpts are engraved into steel using a reduction lathe. Upon completion of engraving however, the tools are in the positive, resulting in what we refer to as Master dies.
These Master dies can then be used to create as many Working dies as will be needed over the course of the production run, as well as utilized to create the differing varieties of this well known, but difficult to acquire dollar.
In order to transfer this positive design into the incuse, or negative, as is needed for coining, these Masters must be pressed into new steel blanks that will serve as the Working dies. This process is know as hubbing. The Master die is secured into the press in the hammer position and a machined steel blank is positioned on the anvil side to be pressed, much like the coin it will create. Under intense pressure (~400 tons) the steel blank is impressed with the device and imprinted in the reverse. This often takes multiple strikes to create a solid impression, not only to show all the details, but to create enough working area to finish the die. Careful attention must be paid to the alignment of the Master and the blank between strikes to avoid any multiple impressions being made out of alignment.
After the impressions are complete the blank is heavily stressed and misshapen from the impact. This blank will be taken back to the machine shop to be turned round again and the proper dimensions and specifications for the working die profile to be machined.
Stay tuned for the release of this desirable reproduction, as well as more posts regarding the techniques we use here at Intaglio Mint to produce fine hand crafted products for your collection!