Coinage
The coinage, now mostly in a mint in accordance with the right to mint coins at the direction of a central bank , is a mechanical process to coins or medals by printing an officially established to give binding and value-creating form. Here, a coin blank is brought into the desired shape with embossing dies . Until the end of the 15th century, coinage was purely manual work ( hammer coinage ). Today minting machines produce 20,000 coins per minute. Significant steps on the way to modern production are the clip mechanism , roller embossing , pocket mechanism , balancer , toggle press and ring embossing . The development of minting techniques is characterized not only by increasing minting speeds but also by efforts to standardize the coin image and the size of the specimens of a coin type.
The motifs and writings imprinted on coins are called embossing (in the broader sense also an expression for coin, medal or brand ).
Main process of coinage
The first documented finds are ionic coins (7th century BC) and were made from electron . A piece of metal was punched with a chisel . From approx. 650 BC. The coins became more artistic and were given simple motifs such as a lion's head and the like ( stater ). From this point on, stamps were used for embossing.
Before that, planets had to be made. It is believed that the flints for Kurant coins were individually cast before they were minted. In the only around 400 BC The minting of bronze coins that began in BC was presumably cast together by several planes and then broken off or pinched off from the cast strand. The early bronze coins of the Roman Republic were only cast and were subsequently not minted.
Hammer embossing
Coins were minted by hand from antiquity to the early modern period (mid-16th century) with hardly any changes in the minting technique. In particular, hammer embossing with an upper, lower punch and hammer was used (see illustration). In the simplest case, a person places a coin blank between the fixed lower die and the hand-held upper die. Improved hammer stamping can be achieved, especially for larger coins, if the upper punch is held and aligned by a second person with flat-nose pliers while the hammer is being struck. A special form of hammer embossing was used on the very thin medieval bracteates , several of which were hammered into a leather or lead pad without a lower stamp. Bracteates are therefore only embossed on one side.
Klippwerk
In the year 1486 a guilder groschen was minted for the first time in Tyrol - the first European large silver coin, from which the thaler later developed. Such large coins can only be beaten with difficulty and often only imprecisely by hand. The Klippwerk was introduced as a major technical innovation for coin minting . The clip mechanism is a mechanical device which, compared to the use of flat nose pliers, allows the upper punch to be guided even more precisely and safely. However, the energy required for coinage is still applied by manual hammer blows.
Roller embossing and pocket work
In the coin to Hall in 1550 was the first time with the roller embossing begun. Metal plates as thick as the later coins ( zaine ) are wedged between two iron rollers. Several negative forms of the front and back of the coins to be minted are engraved in the rollers. While with hammer minting the blanks are made from the zain before minting, with roller minting the coins are only cut out of the zain after minting. The rollers could easily be powered by animals or water power. A further development of embossing with rollers is the pocket work . The rollers each contain only one separately exchangeable upper and lower punch. Pocket works could be operated by one person. In particular, the exchangeability of the stamps was an advantage over roller embossing.
Push mechanism (balancer, screw press)
Widely distributed the invented in the 16th century also impact plant ( Balancing ). The push mechanism is technically a screw press . The (fast) rotary movement of a spindle is converted by a thread into a vertically downward, slower movement. There is a very high pressure between the lower punch and the upper punch at the lower end of the spindle. The effect is increased by centrifugal masses at the upper end of the spindle. With the use of the appropriate stamp and sufficiently large oscillating masses, several coins can be minted at the same time.
Toggle press
Diedrich Uhlhorn invented the toggle press in 1817 , which was used for minting coins just a few years later. The toggle press uses the eponymous toggle effect to (1) place the upper and lower punches on the coin quickly and with little effort, but (2) to be able to use maximum force during the coin minting itself. With this system, the upper punch is also pressed against the coin blank (flute) under increasing pressure. Toggle presses can easily be driven mechanically ( steam engine ) and the insertion of the coin blanks can be automated. Modern coinage is still largely based on the toggle press principle.
Edge processing - knurling, ring embossing
The edge of the coin was generally not designed in antiquity and the Middle Ages. In the early modern period, higher quality coins were often processed by knurling in addition to minting. There have been special knurling machines for making marginal writing or fluting of coins since the 17th century. The knurling of coin blanks usually took place before the embossing.
With the introduction of ring embossing , the embossing and the edge design took place in one operation. Ring stamping describes a stamping technique invented by Jean-Pierre Droz in 1810, in which the coin blank is not only pressed between the upper and lower dies. At the same time, the blank lies in a ring into which it is pressed during the embossing. The ring means that the coins are given a precisely defined edge and diameter. If the ring is also engraved, it acts as a third stamp for the edge embossing. The embossing in the ring can be combined with other embossing processes. Ring minting replaced the knurling of the edge of the coin , particularly for larger coins containing precious metals (especially Kurant coins ). From the second half of the 19th century, small coins were basically minted in the ring.
Stamp and stamp production
Single stamps
The coin engraver engraved to modern times into a single Münzbildnegativ in a still uncured lower punches made of iron a. The lower stamp marks the side of the coin, traditionally referred to as the obverse or obverse (ancient Greek "character"). The image of the holding chisel or upper die forms the reverse or lapel (ancient Greek "typos") of the coin. After the engraving, the upper and lower punches are hardened . After hardening, the stamps are much harder than the coin metals usually used for minting, such as gold , silver and copper or their alloys . Nevertheless, the stamps were subject to high wear and tear and had to be replaced at regular intervals. Since each stamp was a handcrafted one-off piece, the coinage of otherwise identical types of coins also varies.
Stamp production using master stamp matrices
Since the 19th century, increased demands have been placed on coins in terms of the uniformity of their coin designs. Therefore, one began to produce "mother stamp matrices". These matrices bear the “positive” coin image as it is to appear on the coin later. These positive mother stamps are hardened and used for the embossing of almost identical daughter stamps made of unhardened material. These daughter stamps have a negative image and are used for the actual coinage after hardening. For hardening often comes today galvanic hard chrome plating added.
Modern stamps allow many thousands of individual stamps without significant stamp wear. In particular, the dies for coins in circulation today usually have a relatively flat engraved relief.
Stamp position
When minting coins with the help of two stamps, it is determined at the same time how the front and back of a coin relate to one another. With reversible embossing , both sides are correctly positioned when the coin is rotated around the horizontal axis. Since u. a. The coins of the French franc were also minted in this way, which is also referred to as “French minting”. In contrast, there is the reverse coinage . The coin must be rotated around the vertical axis in order to correctly display the coin image on both sides. For example, the coins of the Deutsche Mark as well as the euro coins are designed in reverse stamping. In summary, it can be said that coins that are stored in transparent envelopes in coin albums are correctly positioned when the page is turned over, if they were produced in reverse embossing, while coins with reversible embossing are upside down.
Embossing services
Hammer minting is a time-consuming and slow process - especially with large coins that cannot be minted with a single blow. First advances were made with mechanized roller minting and large push mechanisms that could mint several coins at once. But also the production steps upstream of the actual coinage, such as the production of the Zaine (coin plates), could be greatly accelerated by using mechanized hammers and rollers.
The next great advance was the use of steam engines . In the late 18th century, Matthew Boulton and James Watt built minting machines that could make 60 coins a minute. Ring stamping and steam-powered stamping machines were first used in Boulton's English Soho Mint . Modern minting machines reached 400–500 coins per minute at the end of the 20th century. The new euro coins were minted at 20,000 coins per minute from 2002.
Special coinage
The first 100 coin mints of a new stamp are often used specifically for collector coins. Special coins are made with polished flans and a polished stamp.
See also
- Mintmaster's mark
- Coin and medal signature
- Wardein
- Weimar Mint. The mint from 1622 to 1691 (list and description of the technical equipment from 1691 for minting coins).
- Discount (numismatics)
- Hermaphrodite coin
literature
- Dieter Fassbender : Lexicon for coin collectors. Over 1800 terms from Aachen mark to hybrid coin (= Rororo. Rororo manual. 6292). Rowohlt-Taschenbuch-Verlag, Reinbek near Hamburg 1983, ISBN 3-499-16292-X .
- Klaus Jopp: The country needs new talers. In: The time . 42, October 1998, p. 61.
- Renate Kingma: Coins and Money (= What is what . 78). Tessloff, Nuremberg 1985, ISBN 3-7886-0418-2 .
- Christopher Maynard: Wonderful World of Money. Tessloff, Hamburg 1978, ISBN 3-7886-0158-2 .
Web links
- Film about the production of a coin in the Berlin State Mint
- Embossing tools (mainly from the Berlin Mint) in the interactive catalog of the Münzkabinett www.smb.museum/ikmk
Individual evidence
- ↑ Helmut Kahnt, Bernd Knorr: Old dimensions, coins and weights. A lexicon. License issue. Bibliographisches Institut, Mannheim et al. 1987, ISBN 3-411-02148-9 , p. 384.
- ↑ Münzkabinett Ingolstadt
- ^ Peter Franz Mittag, Greek Numismatics - An Introduction, Heidelberg 2016, p. 24
- ↑ imm coin dictionary. Retrieved November 2, 2012 .
- ^ Numis-Lexicon "K". Retrieved November 2, 2012 .
- ^ Numis-Lexicon "W". Retrieved November 2, 2012 .
- ↑ Numis-Online.ch “Reversible stamping”. Retrieved November 2, 2012 .
- ↑ Numis-Online.ch "Kehrprichtung". Retrieved November 2, 2012 .