The CN Journal Sample Articles

Metallurgical Aspects of Coinage with Special Reference to Nickel

by Aubrey A. Tuttle

Reprinted from The CN Journal Volume 1 Number 1 - 3 Jan - Mar 1956

Address delivered to the Toronto Coin Club, on March 26, 1955, by Aubrey A. Tuttle,
Mechanical Engineer, The International Nickel Company of Canada

In my work, I am concerned with properties and fabrication of nickel, nickel alloys, and competitive materials. I will, therefore, confine my remarks in the main to metallurgical aspects as they concern the government which must provide the raw materials of coinage, the Mint which manufactures the coins, and the people that must use the coins. Some historical comment is included, and a reference to "our Company".
In speaking of "our Company" I use the expression in its broadest sense. First, because nickel has a special significance to all Canadians due to its abundance here and its role in the Canadian economy, I believe we are justified in thinking of it as a distinctively Canadian metal. Secondly, ownership in the company is widely distributed, and it is quite likely that some of you are among its shareholders.
Our company supplies approximately 70% of the nearly four hundred million pounds annually available to the markets of the free world. Of this amount, only three to four per cent goes into coinage. This does not seem like a very substantial amount of nickel. However, when it is remembered that the weight of coins is usually measured in either grains or grams, the amount runs into astronomical figures. For example, if 4% of our Company's production were confined to the Canadian 5 cent piece, it would produce one billion "Nickels". If consumed in the production of the U.S. 5 cent piece, which contains 25% nickel, balance copper, four billion "Nickels" could be minted. Over the years, the allocation to coinage has grown and will undoubtedly do so in the future.
Feely reports, and I quote "In the United Kingdom the withdrawal from circulation of more than two billion quarternary silver coins and their replacement with cupronickel coins of the same denominations will take approximately twenty years to accomplish and it is estimated that the saving on the operation will exceed £30,000,000 at the present prices of the metals involved. Over 27,000,000 fine ounces of silver were recovered in 1949 from the coins withdrawn from circulation.
India adopted pure nickel as the basis of her coinage system in 1946. Up to 1949, together with Pakistan and Hyderabad, she has imported over seven thousand metric tons of nickel in the form of blanks which have been struck by the Bombay and Calcutta Mints. The Ministry of Finance announced in April '49 that the Indian Government is building a refinery for the recovery of three hundred million ounces of silver contained in the quarternary silver coins of India and Pakistan now being replaced by pure nickel. The 1950 issue of pure nickel Indian coins in three denominations carried the inscription "Government of India" for the first time.
The Government of Burma announced the adoption of pure nickel for the one-half and one-quarter Rupee coins, leaving for later consideration the issuance of one Rupee coins. These new Burmese coins are unusually attractive in appearance and remarkable for their perfection of design and detail. Let us consider why nickel has replaced much of the traditional gold and silver used in coinage. The reasons are both metallurgical and monetary.
Metallurgically speaking, nickel has no equal in its combination of properties which makes for ease of coinability, durability, good appearance, and difficulty experienced in attempting to counterfeit. It is also magnetic, unlike all of the other coins with the exception of steel substitutes. Its magnetism is used to advantage in singling it out from other coins, or for use in certain types of vending machines.
The Swiss actually attempted to mint a pure nickel coin back in the 1850's, but owing to the presence of impurities it was brittle and lacked malleability. It was therefore abandoned, and a nickel-copper substitute used until in 1881 the first pure nickel coin was issued. This coin had to await the development of malleable nickel, which was made possible by a discovery of Joseph Wharton of Philadelphia, in 1865. (Wharton patented a magnesium treatment which took care of traces of sulphur in nickel and thus removed the embrittling element.)
Following 1859, when a Belgium Monetary Commission effectually assailed the then prevailing theory that the intrinsic value of coinage must approximate its nominal value, nickel and nickel alloyed copper appeared best suited for token coinage. Surprisingly enough, the first pure nickels which were circulated in Switzerland in 1881 did have an intrinsic value approximating the coin's nominal value, but since that date the Canadian mines have come into production and the price of nickel today is but a fraction of the price at that time.
The first recorded occurrence of nickel in coinage was in a Bactrian coin issued in the reign of King Euthydemus II, in approximately 235 B.C. It was found to contain about 20% nickel with most of the balance being copper. The coin, considered to be a single metal, may have been a natural alloy.
(To be continued)
1 Since 1951 India, Pakistan, and Burma, because of the scarcity of nickel, had to discontinue the use of pure nickel and are using cupro-nickel at present.

The Canadian Numismatic Journal Volume 1 Number 2 February 1956 Pages 28-32
Metallurgical Aspects of Coinage with Special Reference to Nickel
Address delivered to the Toronto Coin Club, on March 26, 1955, by Aubrey A. Tuttle,
Mechanical Engineer, The International Nickel Company of Canada (Continued from January issue)

Since nickel and copper does occur in certain ores in this ratio, a separation would not be required in treating the ores for coinage. 2 The Chinese had previously unearthed some of this ore known as "Peitung" 3 and had for centuries produced metallic articles of this composition which eventually made their way to the Western World. Centuries later in Saxony (Germany) a nickel-containing ore was located which stubbornly resisted the efforts made by miners to refine it. Thinking it to be copper, they called it "Kupfernickel" or bewitched copper, after "Old Nick", who was supposed to have plagued the miners and bewitched their ores. The appearance of the pure metal had to await the discovery of Cronstedt, the Swedish chemist, in 1751, and he appropriately called it "Nickel". 4

Coinage Alloys
The earliest Greek coins were of pure gold and silver or electrum (990-997 fine). Under the Roman Emperors copper was added. Just before the fall of the Empire it was added to the extent that in some cases only 2% of gold was present. In the Middle Ages, this practice of debasing alloys was discarded, and standards of fineness or purity established.
England adopted the gold standard of 22 carats (92%) fine in 1526. The Saxons introduced to England the silver standard of 925 fineness which was not continuously adhered to. In fact, during the reign of Henry VIII, his numerous difficulties caused him to debase the silver coinage until it contained only one-third silver, two - thirds copper. Edward VI lowered it to one-quarter silver. Queen Elizabeth I restored it to the 925 fineness where it remained until the inflationary period following World War I, at which time it was reduced to 50%.
Although many metals other than gold and silver have been used over the centuries, most have been abandoned because of inferior properties. For example, iron was widely circulated in the 5th century B.C. and later in World War I days in both Poland and Germany, where it was used as a substitute for stratetic nickel and copper and scarce silver. Pure zinc has been used in Czechoslovakia, and before the Christian ,era lead was used in Egypt and later in the 17th century in Denmark. Pure tin half-pennies and farthings had a limited circulation in the British Isles prior to 1692. Even the scarce and highly valued platinum found a place in coinage in Russia a little over a century ago. Copper and modifications of it known as bronze, have, of course, been used since the earliest recorded times. Very recently, certain brasses and aluminum bronzes have been popular substitutes and now pure aluminum coins are in circulation in Bulgaria, and India is seriously considering their use. Since the time of the Belgian Commission on Monetary Reform, cupro-nickel and a somewhat later pure nickel were widely adopted as replacements for silver alloys. The low alloy bronzes have, of course, held their position in the lowest denominations because if cupro-nickel or copper were used here, the intrinsic value would approximate their nominal value.

What Determines Choice of Alloy?
Basically, the choice of an alloy for coinage is dependent on avail-ability and properties. The traditional coinage of the past, gold, silver, and copper, has in recent times suffered a decline due to the vast increase in the amounts and circulation of coinage and monetary reforms. Unfavourable trade balances in many countries of the world, with a consequent upset in gold reserves, have seen a virtual disappearance of gold as a medium of exchange. The silver Rupee, which for 100 years was looked upon in India as "Gold" to be cherished and occasionally converted to metal ornaments, gave place to pure nickel in 1946.
Aluminum bronze replaced silver in the French 1 and 2-franc pieces following 1921 and similarly in other countries of Europe.
Copper, originally added to de-base or reduce cost of silver coinage, was soon realized to be advantageous, in that it strengthened and toughened the alloy so that silver coins, alloyed with copper, outlasted the high purity coins with great savings to the State. These more durable coins were also found to be more difficult to deface (clip) or counterfeit. This practice of clipping appears to have been a popular past time especially during the Medieval era, when it was indulged in to the extent that coins decreased in weight and shape more rapidly than could be attributed to wear. This practice gives rise to our modern expression "clip joint".
In practice, most of the alloys that have been used in coins came about by accident rather than by a programme of research. In France, soon after the revolution of 1789, copper was scarce, and to fill the need of coinage church bells were melted down to eke out the supply. It so happened that these church bells were copper alloyed with tin, and occasionally a small amount of zinc; the formulation of experts in this field in order to get clarity and perfection of sound. By mixing the bell alloy with existing copper coinage, they arrived at an alloy of approximately 95% copper, 4% tin, and 1% zinc, which had such excellent wearing properties and, I imagine, a decided ring, that it was adopted by France in 1851, and a number of other countries followed France's lead.
Cupro-nickel, an alloy of approximately 75% copper and 25% nickel, has been popular ever since the time of the Belgian Monetary Commission as mentioned above, and continues on the increase to the present time. In the United States, the cupro-nickel 5 cent piece was temporarily discontinued in May, 1942, to conserve both nickel and copper. The Second War Powers' Act, March, 1942, provided for a U.S. "Nickel" containing 50% copper and 50% silver with provision to vary the analysis in the public interest. After a little research into the property of various alloys, having conservation in mind, the U.S. Mint came out in 1943 with a 5 cent piece containing 35% silver, 56% copper, and 9% manganese. This was discontinued, however, by the end of 1945. It is interesting to observe how the strategic position of various metals has affected the composition of coinage, especially during a crisis. For example, the discontinuance of the substitute 5 cent piece in the United States was made possible by the increase in both nickel and copper towards the end 'of the war.
In 1943, the United States bronze cent was replaced with a zinc-coated cent, which was produced throughout 1943 to the extent of one billion. In 1944 brass cartridge cases became available in sufficient quantity to supply the much needed bronze so that the original copper was again minted. The U.S. 1 cent piece has a composition known as "commercial bronze", which is 95% copper and 5% zinc. The zinc, somewhat higher than many countried use, was due to its occurrence in scrap such as cartridge brass, which has an alloy 70% copper and 30% zinc.
In Canada in 1943, the Tombac "nickel", even more closely resembled the analysis of cartridge brass. It is now being withdrawn from circulation owing to its confusion with coppers. In 1944 and 1945 chromium plated steel 5 cent pieces were used as a substitute for pure nickel, and later during the Korean crisis in the years 1951, 1952, 1953. I read recently, in one of the bulletins of the Tin Research Institute, of efforts to conserve nickel by the use of tin to replace a portion of the nickel in cupro-nickels. It was not possible to reduce nickel below 25% without some deterioration in colour, unless restored by adding a third element such as tin. After some research, the Council came up with an alloy having 15% nickel, 5% tin, which although admittedly a little harder than is desired for minting, they ,considered a suitable substitute, and by lowering the tin to 3% the softness was equal to the cupro-nickel coin. The irony of this proposed substitute impressed me in particular, since during the war there was a great effort made in Ottawa by myself and other members of the Metals Control, to conserve tin. Now, in the view of the Tin Research Council, and as a result of the recent programme of nickel conservation, the tables would appear to be turned within a period of ten years. However, it is our feeling that the long-run position for nickel is definitely more secure than is tin, which is largely recovered from countries bordered by, and in some cases dominated by, Russia. Moreover, the durability of nickel and high nickel alloy coins is a fact of everyday observation. Copper and bronze coins become greasy and soiled in circulation. It has been found that the grease contains fatty acids, which corrode the copper, forming a superficial, friable crust which is continuously rubbed off. Thus the excellent corrosion resistance of nickel and nickel-copper alloys is a decided advantage in its use.
By May of last year, the Royal Canadian Mint returned to pure nickel. Requests to tender for 10,000,000 nickel blanks were sent out at that time, and many of these have been coined into shiny new 1955 "nickels" and are now in circulation.

A Mint is defined as a place where coins are manufactured by authority of the State. Money, in the 'sense that it means any medium of exchange, was used long before recorded history. Even eight thousand years ago the Chinese had a form of money, but coins did not appear until approximately 700 B.C.
The Ancients soon learned to appreciate a metallic medium of exchange because at that time it must be remembered that all metals were highly valued and they possessed a superior appearance and greater durability than other forms of exchange.
Soon simple die marks were used to indicate the value or authenticity of coins. A wedge-shaped die known as a "coin" and a hammer was used to mark the blank, thus the metal was "coined" and the metal so 'stamped became known as a "coin". According to Herodotus, the first mint was established by Gyges of Lydia by the end of the 8th century B.C. for coining of gold, silver, and electrum. Silver was coined on the Island of Aegiana and the art was introduced by the Greeks into Italy, Persia, India, and countries bordering the Mediterranean. Later the Romans laid the foundation of modern minting, and the art originated quite independently at a later date in China, and spread to Japan and Korea. The Romans, at first, cast their large copper coins, but it was soon realized that the perfection of form found on many of the ancient, as well as many of the modern, coins, could not be achieved by a casting technique.
In the kingdom of Europe, the supply of bullion often came from mines owned by the king. The right of seigniorage was often waived to encourage subjects to bring gold and silver to the mint. In spite of this, supplies were usually short and the alchemists enjoyed a heigh-day in trying to effect the transmutation of base metal into gold.
In Britain, coining preceded the Roman conquest. Later, following the Norman invasion, there were 70 or more mints throughout the British Isles — this is a greater number than now exists in the whole world. The large number was due to low production techniques and lack of transportation. Coins were periodically tested at Westminster to check on the weight and fineness, and to 'do so required a staff of nearly 1,200 supervisory officers. These officers, on behalf of the king, also collected seigniorage, which was generally a deduction from the amount of bullion sent to the mint for coinage, but work was done by contractors at great profit. Sir Isaac Newton was appointed Master of the Mint and Contractor of the Coinage in recognition of his services. The London mint was built in 1810, and in 1850 the contract system was abolished, since which time the work has been done by Civil Servants with profits going to the State.
In India, hand minting persisted in native states until the 19th century. The first Rupee of modern times was struck on August 29th, 1757, in Calcutta. The coin's were crude, struck between dies with a hammer. Rolling mills, drawn by about 40 coolies, were used. Melting was done in a large open fire of charcoal, where the heat and fumes were often severe enough to drive away the most vigilant inspector. Under these circumstances, the job was no doubt profitable to the melters.
In 1824 the Indian Government established two mints, one at Calcutta and the other at Bombay, which were among the largest in the world at that time with the exception of the Philadelphia mint.
(To be continued)
2 Feely reports that the alleged use of a natural alloy in the Bactrian coins is still a moot question.
3 Feely prefers use of the term "Peitung" (white copper) in describing Chinese cupro-nickel to the Cantonese expression `Paktong' or `Pakfong' which was formerly used.
4 Feely is currently conducting research into the derivation of the word. "nickel" as the above explanation is not definitely established

The Canadian Numismatic Journal Volume 1 Number 3 March 1956 Pages 51-52
Metallurgical Aspects of Coinage with Special Reference to Nickel
(Continued from February issue)

In March of 1952, a new modern mint was constructed at Alipore, which absorbed the Calcutta mint and has a capacity of over a million coins per eight-hour shift.
In U.S. the first mint was set up in Boston in the year 1652. This mint coined the famous "Pine Tree Shilling". Nearly a century and a half passed before the Philadelphia mint came into operation in 1792. The coinage produced by the Philadelphia mint was as set out in the U.S. Constitution, based on the dollar, owing to the prevalence of Spanish dollars in circulation.
In Canada, prior to 1858, coinage was mainly of British, U.S. and Spanish origin. From this date until 1908, the British North American provinces, and later Canada, obtained coinage from the London and Birmingham mints. In 1908 the Ottawa mint came into production as a branch of the Royal Mint. In 1931 it came under the jurisdiction of the Department of Finance and was renamed the Royal Canadian Mint. In addition to handling domestic coinage, which now includes Newfoundland, it has supplied much to Jamaica and other West Indian countries. It also produces medal-lions and commemoratives pieces, and refines, essays, and acts as a depository for gold.
Modern Minting
In ancient times, as well as the Middle Ages, the production of coinage was largely a hand operation and their quantity restricted. The ordinary man depended more on the barter system for his daily requirements.
Modern methods may be said to date from 1553, when in Paris rolls were used to reduce cast bars, punch presses for production of blanks, and screw presses for coining. England experimented with this equipment shortly after its introduction to France, but nearly a century passed before she adopted them.
In the 18th century a Buckingham manufacturer named Boulton, together with inventor James Watt, first applied steam to the working of coinage machinery. In 1839 Uhlhorn developed the lever press which replaced screw presses. The modern descendant of this press utilized the toggle principle and is capable of striking coins in excess of 160 per minute.
Our Ottawa mint is currently in the midst of an expansion programme, which will ultramodernize it and increase its productive capacity nearly three times. It is expected .to be in full swing before the end of the year. The annual requirements for coinage in Canada have grown and in recent years have exceeded one hundred million pieces (nickel averages about 15% of the production). During the War, three shifts were necessary and in spite of this, there was still a shortage. The new plant will adhere to the single shift, regular civil servant's hours, and is expected to be able to handle all the requirements for years to come.
Four new 200 pound melt induction furnaces have been added to make six furnaces in all. These are capable of pouring 200-pound heats into vertical water-cooled permanent molds, producing a slab 1½" X 8" X 4 ft. These slabs are conveyed to a new continuous rolling mill manufactured by Dominion Engineering. The mill consists of two sets of rolls, First, roughing rolls will handle the slabs, which are automatically passed between the rolls 7 or 8 times and thence automatically to the finishing rolls where the very much elongated slab is cooled during its first pass and handled in coil form for succeeding passes. When the coil is reduced to the required thickness, it is passed to a slitter where it is sliced into three 2" wide coils. These are transferred to 2 blanking presses where coin blanks are punched from the strip at high speed. The remaining scrap is chewed up into a size suitable for remelting.
At this stage the metal has been quite severely worked and must be annealed or softened prior to the actual coining operation. The blanks are placed in furnaces and brought up to the appropriate temperature for softening, about 1,450 degrees F, depending on the alloy, after which they are pickled to remove scale resulting from the high temperature operation and conveyed to an edging machine which smooths the edge and raises it slightly, to protect the face of the coin from wear. From here, the coin blanks are delivered to one of twelve modern, high speed Taylor and Challen coining machines made in Birmingham, England. These machines vary in capacity from 30 to 250 tons and in speed from 100 to 160 strikes per minute.
The coins are now ready for final inspection, packaging and shipment to various agencies of the Bank of Canada.
For much of the content of this paper, I am indebted to Messrs. C. E. Macdonald, E. F. Feely, and R. J. Edmunds. Mr. Macdonald, who is Manager of Canadian Sales, Development and Research, has for years championed the cause of nickel throughout Canada and has maintained frequent contact with the Royal Canadian Mint in Ottawa. In 1920 he approached Sir Henry Drayton and presented arguments for nickel. He was instrumental in the issuance of the Commemorative Cronstedt Nickel of 1951. Mr. Feely, operating from our New York Office, has actively promoted nickel for coinage through-out the rest of the Western Hemisphere.
Mr. Edmunds, who was Chief of the 'Coining and Medal Division of the Ottawa Mint, and has now retired, has generously furnished information from his own personal files, and answered many of my questions relating to the operations of the Mint. I have also drawn much from our company publications, press clippings, and that ever-reliable Encyclopaedia Brittanica.

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