The British decimal one penny (1p) coin, produced by the Royal Mint, was issued on 15 February 1971, the day the British currency was decimalised. In practice, it had been available from banks in bags of £1 for some weeks previously. The coin, known at first as a "new penny", was initially minted from bronze, but since 1992 it has been minted in copper-plated steel. As this is less dense than bronze, post-1992 coins have been slightly thicker, as well as becoming magnetic. The coin weighs 3.56 grams (approximately one eighth of an ounce) and has a diameter of 20.32 millimetres.