British Half Penny coin

100 The British decimal Half Penny or Ha'penny coin was issued on 15 February 1971, the day the British currency was decimalized. In put into practice it had been available from banks in bags for some weeks previously.

The main idea behind the coin's configuration was to enable certain pre-decimal coins—most notably the sixpence—to remain in circulation during the transition to decimal coinage; in the same vein a decimal quarter-penny coin was also proposed, but ended up never being formed.

The coin was minted in figurine. The coin weighed 1.78 grams and had a diameter of 17.14 millimeters. It was the smallest coin used in the decimal currency coinage by both size and value, and was nicknamed the "tidier" on account of its size. By the early 1980s its value was minimal and its main utility was as a useful driver of small screws. The 1984 half penny was only issued in mint and proof sets by the Royal Mint, and the coin was demonetized and withdrawn from circulation in December 1984.

The reverse of the coin, designed by Christopher Ironside, was simply a crown, with the fraction "½" below the crown, and either NEW PENNY or HALF PENNY above the crown.