Twenty pence (British coin)
Note that this article does not refer to the 14th century English gold Twenty Pence coin.
The British decimal Twenty Pence (20p) coin was issued in June 1982 to fill in the obvious gap between the Ten Pence and Fifty Pence coins; it rapidly gained common acceptance and is probably the most common of the current 'silver' British coinage.
The coin is minted from an alloy of 84% copper and 16% nickel (unlike the other 'silver' coins which are 75% copper, 25% nickel), weighs 5.00 grams and has a diameter of 21.4 millimetres. Note that the coin is not circular but seven-sided to aid identification -- the sides are not straight but are curved so that the centre of curvature is the opposite apex of the coin, this allows the coin to roll freely in slot machines.
The reverse of the coin is a crowned Tudor Rose, with the numeral "20" below the rose, and the date and TWENTY PENCE above the rose. Uniquely in modern British coinage, much of the inscriptions are incuse i.e. the lettering is punched into the coin rather than standing proud of it.
During the history of the coin, three different obverses have been used so far - between 1982 and 1984 the head of Queen Elizabeth II by Arnold Machin was used, between 1985 and 1997 the head by Raphael Maklouf was used, and since 1998 one by Ian Rank-Broadley has been used. In all cases, the inscription used is ELIZABETH II D.G.REG.F.D.
See also British coinage.