The science behind the shape of the 50p celebrated on a special anniversary coin

Replacing the ten-shilling note with a coin posed a unique set of challenges. The new coin would be the largest denomination in circulation, so it needed to stand out in a handful of change without being too heavy and bulky.
Calling upon the services of Bristol Siddeley Engines design office, which usually worked on aircraft such as Concorde, Hugh Conway and his team of engineers perfected their radical design – a seven-sided coin, easily distinguishable by touch and sight, that would still roll smoothly in vending machines.
As we celebrate the 50th anniversary of one of the nation’s best-loved coins, this gold Proof commemorative 50p pays tribute to the precision engineering behind its revolutionary shape.