From 1947 onwards, all British general circulation silver coins were made from a copper nickel alloy. Since Victorian times, all British general circulation "old currency" Pennies were made from bronze.
Bronze
Also used for the farthing 1/4 Penny coin
The Royal Mint produced 369,989,130 British One Penny coins in 1986.
The metal composition of penny coins made after 1982 is 97.5 percent zinc and 2.5 percent copper. The first penny coins, from 1793 to 1837, were made from pure copper.
There were 26,977,000 British 1902 Pennies minted.
There are approximately 20 modern British coins that have been retired. Some of those include: farthing, half penny, groat, guinea, penny, threepence, and one shilling.
The King's Norton Metal Company Birmingham (KN) minted many British copper and bronze coins over a period of years. No British coins were minted from 1920 onwards, but they continued to mint coins for other countries. There were only 7 or 8 British 1933 Pennies minted by the Royal Mint London and none of them were released into circulation.
No British coin is magnetic. Prior to 1992 all British coins were made from non-ferrous metals. The copper-plated steel 1 Penny and 2 Pence coins were first issued in 1992. The nickel-plated steel 5 Pence and 10 Pence coins were first issued in 2011. These are the only British coins in circulation that can be attracted to a magnet since steel is an alloy of iron, a ferrous metal.
Modified coins have no collector value.
The British decimal Penny weighs 3.56 grams.
A "Penny Farthing" is not a coin, it was a very popular 19th Century bicycle invented in 1871 by British engineer, James Starley. It was called a "Penny Farthing" because of the disparate size of the two wheels, which were likened to a "Penny" and a "Farthing". There were Penny coins and Farthing coins, with four Farthings (Fourthings) to the Penny. Make up your mind which coin you have and resubmit your question.
The mint is looking into new metal compositions for the penny and nickel.
There are no British magnetic Pennies. From 1992, the Royal Mint began making the British Penny and 2 Pence coins from copper plated steel. Because they are made from steel, they can be attracted to a magnet. All years of issue of the British decimal Penny and 2 pence coins are still potentially in circulation, so they are worth 1 Penny and 2 Pence respectively.
There are no British Pennies with pigs on them. All British One (New) Penny coins have a Crowned Portcullis with chains on the reverse.