The specifications of the bronze version of the penny were a mass of 9.45 g (0.333 oz) and a diameter of 30.86 mm (1.215 in), and remained as such for over a hundred years.
Pennies were minted every year of Queen Victoria's reign, and every year of Edward VII's reign.
George V pennies were produced every year to the same standard until 1922, but after a three-year gap in production the alloy composition was changed to 95.5% copper, 3% tin, and 1.5% zinc, although the weight and size remained unchanged (which was necessary because of the existence by then of large numbers of coin-operated amusement machines and public telephones).
Thereafter, pennies were minted every year for the remainder of George V's reign, although only six or seven 1933 coins were minted, specifically for the king to lay under the foundation stones of new buildings; one of these coins was stolen when a church in Leeds was demolished in the 1960s, and its whereabouts is unknown.

A few pennies of Edward VIII exist, dated 1937, but technically they are pattern coins i.e. coins produced for official approval, which it would probably have been due to receive about the time that the King abdicated.

Pennies were not minted every year of George VI's reign.
Pennies minted in 1950 and 1951 were for overseas use only.
One 1952 penny, believed to be unique, was struck by the Royal Mint.
The worldwide shortage of tin during the Second World War caused a change in the alloy in 1944 to 97% copper, 0.5% tin, 2.5% zinc, but this bronze tarnishes unattractively, and the original 95.5% copper, 3% tin, 1.5% zinc alloy was restored later in 1945.

Because of the large number of pennies in circulation there was no need to produce any more in the 1950s, however a large number of specimen sets were issued in 1953 for Elizabeth II's Coronation.
At least one 1954 penny was struck, apparently for private internal purposes at the Royal Mint, but it was not until 1961 that there was a need for more pennies to be minted, and production continued each year until 1967, and afterwards (as pennies continued to be minted with the date 1967 until 1970).
The 97% copper, 0.5% tin, 2.5% zinc alloy was used again for the 1960s pennies.
Finally, there was an issue of proof quality coins dated 1970 produced to bid farewell to the denomination.
The specifications of the bronze version of the penny were a mass of 9.45 g (0.333 oz) and a diameter of 30.86 mm (1.215 in), and remained as such for over a hundred years. Pennies were minted every year of Queen Victoria's reign, and every year of Edward VII's reign. George V pennies were produced every year to the same standard until 1922, but after a three-year gap in production the alloy composition was changed to 95.5% copper, 3% tin, and 1.5% zinc, although the weight and size remained unchanged (which was necessary because of the existence by then of large numbers of coin-operated amusement machines and public telephones). Thereafter, pennies were minted every year for the remainder of George V's reign, although only six or seven 1933 coins were minted, specifically for the king to lay under the foundation stones of new buildings; one of these coins was stolen when a church in Leeds was demolished in the 1960s, and its whereabouts is unknown.
A few pennies of Edward VIII exist, dated 1937, but technically they are pattern coins i.e. coins produced for official approval, which it would probably have been due to receive about the time that the King abdicated.
Pennies were not minted every year of George VI's reign. Pennies minted in 1950 and 1951 were for overseas use only. One 1952 penny, believed to be unique, was struck by the Royal Mint. The worldwide shortage of tin during the Second World War caused a change in the alloy in 1944 to 97% copper, 0.5% tin, 2.5% zinc, but this bronze tarnishes unattractively, and the original 95.5% copper, 3% tin, 1.5% zinc alloy was restored later in 1945.
Because of the large number of pennies in circulation there was no need to produce any more in the 1950s, however a large number of specimen sets were issued in 1953 for Elizabeth II's Coronation. At least one 1954 penny was struck, apparently for private internal purposes at the Royal Mint, but it was not until 1961 that there was a need for more pennies to be minted, and production continued each year until 1967, and afterwards (as pennies continued to be minted with the date 1967 until 1970). The 97% copper, 0.5% tin, 2.5% zinc alloy was used again for the 1960s pennies. Finally, there was an issue of proof quality coins dated 1970 produced to bid farewell to the denomination.
Penny (British pre-decimal coin)