In the money

The continuing role of nickel in coinage

December 08, 2015

Pic: Royal Canadian Mint

Nickel has a long—very long—history as a metal important to coinage and commerce. While pirates may have hoped for gold and silver, governments, being more practical, were looking for materials that suggested “worth” to their citizens in how the coins looked and felt but without costing more than their face value. For over a century and continuing today, nickel has delivered that value in very durable forms.

What users want
With a pocket full of change, citizens want coinage that is easily recognizable by shape and colour. And having substance but not too heavy. And a pleasing appearance.
There has to be a balance between the value stamped on any coin and the perception of its value. If the relationship between size/weight gets out of balance or if the coins wear quickly in use there will be complaints and, in a psychological sense, an erosion of respect for the coinage.

What governments and mints want
Governments, and the mints that supply them, pay close attention to how citizens perceive their coinage in terms of appearance, usability and safety. At the same time, there needs to be a profit. The profit—“seigniorage”—is the difference between the face value of the coin in question and the cost of producing that coin, of which the materials that go into making it are usually the principal cost. The seigniorage goes to governments and for that reason governments press mints to reduce costs while maintaining the positive image of the national coinage.

For their part, mints have worked hard to respond to or anticipate changes in the cost of the materials they use. As professional organizations in an intensely competitive market for export sales and for commemorative and collector coin sets, they need to have materials that allow them to produce attractive and durable products at an acceptable cost.

What nickel gives
If cost were not a consideration, there would be much more nickel in coinage. Most commonly in alloy form with copper (cupronickel), nickel-containing alloys are extremely hard-wearing and do not tarnish, thus preserving their pleasing appearance. At the same time, the coins can achieve the desirable balance of just enough weight in relation to their face value.

The presence of nickel also allows great precision in design and variation in relief. It varies with the amount of nickel in the alloy but when a nickel-containing coin blank is struck (stamped), any design is transferred with great fidelity. The ductility of the alloy moderates the amount of energy needed to strike a coin as well as reducing the die wear. Yet the toughness of the alloys means that the coin can remain in service for decades with only moderate signs of wear.

Nickel plating and nickel alloying also provide a distinctive electromagnetic signature, which allows counterfeit coins to be rejected by vending machines. As for many products, there is a constant struggle between costs and performance. So far and for the future, the aesthetic and performance of nickel and nickel-containing alloys will continue to give value for money.

More “silver” for less cost
- nickel-plated steel coins
The last two decades have been eventful for the world of coinage, with new alloys, new combinations of alloys, and new security features for high value coins. The common thread in most of these high quality coins is, in varying forms and quantities, nickel. And that includes new applications of an old technology: nickel plating.

Why nickel-plated steel
Every material and design choice involves compromise. When the costs of base metals such as copper and nickel fluctuate and periodically achieve high prices, the economics of coining (and the amount of seigniorage received by governments) may be adversely impacted. That has encouraged much innovation in coinage design and materials.

A clear economic and aesthetic winner is the plating of steel coins with nickel. In the case of the Royal Canadian Mint, a typical coin—the 25 cent piece, for instance—is a multi-ply construction using copper and nickel plating on to steel. The resulting coin is composed of 94% steel, 3.8% copper and 2.2% nickel.

This produces a coin blank that, when struck, is malleable enough to take a strong image, tough enough to serve for decades and is an attractive “silver” colour. It also has a well-defined electromagnetic signature that makes it difficult to counterfeit for vending machine use.

The Royal Mint plating process

Minting coins for export is a highly competitive business and nickel plated coinage is no exception. While the UK’s Royal Mint has a long history—founded in 886 AD—it remains innovative and was an early pioneer in the development of plating technologies for coinage in the 1980s. Unlike the Canadian multi-ply approach, the Royal Mint uses a single layer of nickel on steel—up to 25 microns versus six microns in the final multi-ply layer by the Royal Canadian Mint.

There are differences in costs and performance that the respective mints will explain to potential customers. They all, however, produce coinage that is attractive, durable and do so at competitive cost and they all use nickel.

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