What is meant by the term bimetallic coin ?... Although this concept has a variety of nuanced definitions, here at WBCN, it signifies a coin that consists of two or more distinct metallic parts. These components include an external disc and an inner core, coinciding in shape either in obverse and on reverse. This definition does not encompass coins that have inlaid or plated parts on just one side, either obverse or reverse. For such a coin to be considered bimetallic, the inlaid or plated parts must coincide in shape on both sides. The fundamental, distinguishing feature of a bimetallic coin is the existence of different metallic rings, and not the fact that it consists of an alloy containing two metals.

BIMETALLIC COIN COLLECTION MANAGER

We are glad to present the Bimetallic Coin Collection Manager, an interactive Excel file with months of hard work and compilation of bimetallic coins minted around the world that will help you in the management of your collection. The file will be updated two times per year. Explore the file clicking here:

A BRIEF HISTORY

The basic idea underlying bimetallic coinage is nothing new. The prototypes widely considered to be the earliest bimetallic coins date back to the 18^th century. However, the first bimetallic coin to enter mass circulation in modern times was the Italian 500 lira coin issued in 1982 by the mint of Rome. Bimetallic coins are now produced around the world by over 150 countries - a number that continues to grow annually. These coins are minted in two main substances - precious metals and base metals. Coins minted in the former category consist of various combinations of metals, including platinum, gold, palladium, silver, tantalum, and titanium or niobium of different colors.

On the other hand, mintage belonging to the latter category is composed of metals such as aluminum, stainless steel, aluminum bronze, nordic gold, alpaca, and combinations of copper or brass and nickel, etc.

HOW ARE THEY MADE?

There are some methods of joining the bimetallic blanks. In some of theses the external ring is manufactured by a multiple-die progressive tool, which pierces out the centre hole prior to blanking from a strip. The raised outer edge of the blank, formed by "rimming" assists in reducing the coining pressure.

The inner, or "dump" is made very much like an ordinary coin blank, except for the special milling applied to the edge. When the two components are struck by the assembling press, the outer ring deforms to flow inside the milled indentations, providing efficient anti-twist locking and increasing the strength of the bond. There are other ways of joining bi-metal blanks, with each manufacturer having their own preferred method.

A LOT TO CHOOSE

Not all bimetallic coins are the same. Indeed, this category comprises a range of more specific types of coins, including trimetallic, quadmetallic, shaped or nonconcentric coins, and many others.

Examples of the various kinds of bimetallic coins abound. For instance, in 2017 Mauritania minted the trimetallic 20 Ouguiya coin, and in 2007 the British Virgin Islands minted the quadmetallic 1 Royal coin. Also among the bimetallic category the twelve-sided trimetallic non-concetric 300 Euro coin from Spain and the fourcoloured titanium 1 Crown coin from the Isle of Man.

NOTE: WBCN features only those coins that have been minted and issued with the official support of their corresponding Sovereign State or Dependent Territory, regardless of their current circulatory status.