The pre-decimal threepence (3d), usually simply known as a threepence or threepenny bit, was a unit of currency equalling one eightieth of a pound sterling, or three pence sterling. It was used in the United Kingdom, and earlier in Great Britain and England.
Maundy Threepence have been issued for centuries (they are still being struck today for ceremonial purposes), and initially the circulating threepence were identical in design. Starting in 1927, they were made different - first with a design featuring three oak sprigs then this one with a Tudor Rose, while the Maundy threepence continued with the traditional crowned numeral reverse.
The composition is 0.500 silver, with 0.0227 oz ASW (ounces of Absolute Silver Weight).
This type was only issued for King George VI, and only until 1945 (almost all the 1945 examples were subsequently melted down). A twelve-sided nickel brass threepence was also introduced in 1937; the two formats were issued in parallel until the brass version finally supplanted the silver threepence. The nickel-brass threepence took over the bulk of the production of the denomination, being produced in all years between 1937 and 1952 except 1947.
The silver coins remained in circulation until "Decimal Day", 15 February 1971, and ceased to be legal tender after 31 August 1971. Unlike some of the larger denominations, they were not re-denominated to a decimal value when the decimal Pound Sterling was introduced. | 
