Have you ever noticed that many coins have engravings around their edge, usually in the shape of miniature vertical lines? These edges are usually referred to as reeded or milled in the United Kingdom, and ridged or grooved in the United States of America.

Early coins had smooth edges. As they were made of precious metals – gold or silver – unscrupulous people would shave off some of the metal around the edge and still pass on the coins at face value. Every now and then, the issuing authorities had to take all coins out of circulation, melt and re-mint them to have their face value correspond to the bullion value of the precious metal. That was a costly exercise, but the alternative was even worse, for sooner or later everyone would refuse to accept shaved coins as a legal tender.

With the birth of mechanised minting in the Renaissance Italy, it became possible to engrave the circumference of coins and thus prevent the scraping of even the tiniest piece without detection.  This technology passed from Italy to France in mid-16th century, and then spread to other countries. At first, the edge of the coin was decorated with an inscription or, more often, with a repetitive pattern of plants and abstract elements. The simple vertical lines were introduced later on.

The practice of reeding (or graining, as it is sometimes called in numismatic circles) continued even when the need for it was gone; that is, when authorities stopped minting circulation coins from precious metals. After all, those milled edges still have practical purpose: they help blind people identify a coin’s denomination and they make it more difficult to counterfeit coins.

And did you know…?

• The 2017 British bi-metallic, twelve-sided one-pound coin that has caused hype among coin collectors (or would-be collectors-cum-investors), similar to the hype surrounding South African R5 Mandela coins, has milled edges with grooves on alternate sides.
• When the Veld Pond was minted in 1902, care was taken to give the coin milled edges, despite the extraordinary conditions surrounding its birth in the last few months of the Second  Anglo-Boer War. The Veld Pond was made of gold and is today probably the most valuable among the ZAR collectible coins.
• The bi-metallic South African R5 coin, introduced in August 2004, has a groove in the middle of the milled edge, making it look from profile as if two coins were joined together. What’s more, the groove bears the inscription SARB  R5 in raised lettering, repeated ten times.