Q. David Bowers
The Die-Making Process in 1896
The following is by Chief Engraver Charles E. Barber and is from the Report of the Director of the Mint, 1896:
"Coinage and medal dies are prepared in the following manner: When a coin or a medal is required, the first thing to be obtained is the design .... After the design for the coin or medal is settled upon, the engraver prepares a model in wax, or any material he may prefer to use, of the design selected, or as much of it as he may think most desirable for the production of the medal or coin. The model is generally made three, four, or five times as large as the finished work is intended to be. When the model is finished an electrotype is made. This electrotype when sufficiently strong is prepared for the reducing lathe, and a reduced copy is made the size required for the coin or medal, as the case may be.
"The reducing lathe is a machine, working somewhat upon the principle of the pantograph, only in this case the one point traces or follows the form of the model, while another and much smaller point made in the form of a drill cuts away the material, and thus produces a reduction of the model. This process of reducing the design from the model is necessarily a very slow operation, as accuracy of the reduction depends entirely upon the slow motion of the machine and delicate handling of the operator. While it is not in the power of the operator or machine to improve the model, it is quite an easy matter, if not properly managed, for the machine to distort or the operator to lose the delicacy of the model. The reducing machine can work either from a model in relief or intaglio, though the relief is more often used, and is considered the better way.
"In describing this process, I have said the engraver makes a model of the design he wishes to produce, or as much as he thinks desirable. To explain more fully, I would say some designs or parts of a design are not calculated for reducing by machine, and therefore the engraver only reduces so much of the design as he knows from experience will give the desired effect; the rest he cuts in ... with gravers and chisels. When the reduction is made by the machine from the model it is then taken by the engraver and worked over and finished in all the detail and delicate parts, as the machine does not produce an entirely finished work. Whenfinished by the engraver it is hardened and tempered. If the reduction has been made intaglio, when hardened it is completed and is called a die, and coins or medals can be struck from it; but if in relief, it is called a hub, and the process of making a die from it commences, which is done as follows:
"The hub or relief being made hard, a piece of steel is prepared in the following manner to receive the impression of the hard hub: Take a block of steel sufficiently large to make your die, and carefully anneal it until it is quite soft. This is done by heating the steel to a bright red and allowing it to cool very gradually, being careful to exclude the air by packing the steel in carbon. The steel being soft, turnoff the surface of the block of steel and smooth it before you commence the process called hubbing , which is as follows:
"Place the block of soft steel under the plunger of a strong screw press; then put the hard relief or hub on top of the soft steel, and bring down your plunger with a good sharp blow. This will give you an impression upon the soft steel. In order to make a proper impression, the process of annealing the steel and the one just described, called hubbing, must be repeated many times, until you have a perfect impression of the hub. This being obtained, you have a die which only requires being hardened and tempered to be ready for use. This process of making dies is followed for coinage and medal dies of the most artistic character ....
"To harden the steel dies, they are packed in cast-iron boxes filled with carbon to exclude the air, and when heated to a bright red are cooled suddenly with water. As this would leave them too hard, and liable to crack and break on the edges, the temper is what is technically called drawn, which is done by gently heating until you notice a color appearing upon the surface of the steel. A light straw color is a good color for cutting tools, but dies are generally brought to a deeper color, and in some cases to a blue."
An excellent illustration of a commemorative coin whose dies were prepared according to Barber's 1896 formula is the 1900 Lafayette silver dollar. Certain details of the die were not included in the model but were finished by hand, by the use of gravers and punches, thus accounting for slight die differences and the creation of die varieties. On the other hand, later issues incorporated all of the details in the model including lettering and the date, the 1936 Elgin Centennial half dollar being a typical example.
About Assay Coins
During the years before 1980 additional specimens of commemoratives and regular issues were produced at the various mints to be set aside for viewing by the Assay Commission, which met at the Philadelphia Mint once each year, early on the calendar, to review the nation's coinage for the preceding year and to be sure that statutory requirements were being met. A discussion of assay coins is appropriate here.
In connection with studying the mintage figures given for each coin in the following text, you will observe that for issues of the 1892-1954 era the notation will be found that, in addition to pieces struck for regular distribution, further specimens were made for assay purposes. Examples are provided by the coinage in 1892 and 1893 of 5,002,105 Columbian Exposition half dollars, equal to the authorized mintage of 5,000,000 pieces plus 2,105 extra pieces for assay; the mintage of 1920 Maine Centennial half dollars totaling 50,028, equivalent to 50,000 intended for distribution and 28 for assay; and the 1928 Hawaiian Sesquicentennial half dollar produced to the extent of 10,008, with the odd eight being assay coins.
The Annual Report of the Director of the Mint, 1935, gave a detailed description of the Assay Commission's findings for the previous fiscal year, 1934, and is representative of the procedure. I quote:
"Assay Commission's Annual Test of Coin: Section 3547 of the Revised Statutes provides for an annual test of the domestic coinage executed during each calendar year by a commission, of whom part are ex-officio members, the others being appointed, without compensation, by the President. The purpose is to secure a due conformity in the gold and silver coins to their respective standards of fineness and weight. The Commission, which met at the Philadelphia Mint, February 13, 1935, reported the following results of their ex-amination of the 1934 coinage: