Brass threepence

The brass threepence, or "threepenny bit", was a twelve-sided British coin equivalent to 1⁄80 of a pound. Struck between 1937 and 1967, with a final issue for collectors dated 1970, it was the first British coin that was not round.

By the mid-1930s, the heavy weight of the bronze penny and its fractions had become an issue for firms such as transport companies, that dealt with them in bulk. The silver threepence was unpopular in England due to its small size. The Royal Mint decided on a nickel-brass twelve-sided coin readily distinguishable from other coins due to its size, shape and colour. The initial reverse design, by Frances Madge Kitchener, of a thrift plant, was altered at the direction of the Royal Mint by Percy Metcalfe without Kitchener's knowledge, but threatened legal action by her was settled with a joint statement to the press.

The new coin was slow to circulate when released to the public in 1937, but eventually gained the public's liking, so much so that the silver threepence was discontinued in 1945. A new design, with a crowned portcullis, was instituted for Elizabeth II's initial coinage in 1953. The coin continued in commerce until the decimalisation of the pound in 1971, after which it rapidly vanished from circulation and lost its status as legal tender after 31 August 1971.