If you intend to "scrape" the copper off for personal gain, most countries have laws concerning the mutilation and disfigurement of their coins.
British coins of copper appearance, the 1 and 2 Pence coins, are made from copper plated steel. British coins of silver appearance, the cupro-nickel 5, 10 and 50 Pence coins, are made from 75% copper and 25% nickel. British 20 Pence coins, are made from 84% copper and 16% nickel.
Pure copper has not been used to make British coins for about 150 years. From 1860, British "copper" coins were made from bronze which consisted mostly of copper varying from 95 to 97% copper. From 1992, British "copper" coins were made from copper plated steel. Ironically, copper is used to make modern "silver" coins (cupro-nickel) consisting usually of 75% copper and 25% nickel.
If you refer to the scrap value of the copper, there is no copper in British "copper" coins these days.
The were no British or Australian coins made from pure copper in 1915. Pennies, Halfpennies and Farthings were made from bronze which was about 97% copper.
The copper content of 20th century British predecimal Pennies, Halfpennies and Farthings varied from 95.5 to 97%. When the use of silver in coins was discontinued after 1946, all British "silver" coins were made from a copper-nickel alloy consisting most commonly of 75% and 25% nickel.
There were no copper 50 Pence coins minted, they are all made from a copper/nickel alloy giving them a silvery appearance. If your coin is copper coloured, it is either very seriously tarnished or somebody has plated it. Modified coins have no collector value.
British copper coins changed from copper to bronze in 1860. Bronze as used in British coins, is more than 95% copper and the addition of a few percent of tin and zinc makes a stronger and more durable coin. The exact percentages varied slightly during the course of the 20th century.
In 1892, British coins were made as follows - Pennies, Halfpennies and Farthings were made from bronze. Crowns, Halfcrowns, Florins, Shillings, Sixpences, Threepences and Maundy coins were made from 0.925 sterling silver. Sovereigns and Half-Sovereigns were made from 22 carat gold.
Until 1919, the Halfcrown coin was made from 92.5% silver. From 1920 to 1946, the Halfcrown coin was made from 50% silver. From 1947 to their last minting in 1970, the Halfcrown coin was made from a copper and nickel alloy.
No. Ireland used British currency from about 1830 to 1927.
No. They would be worth far more than 10 pence if they were made from Silver. The British 10 Pence coins are made from 75% copper and 25% nickel. No circulating British coin has any silver content.
Because the British empire in 1805 had a shortage of bullion (gold and silver), copper coins were still produced on a contract-basis at the Soho Mint and the price of copper had risen, making it impractical for them to issue copper coins. This eventually lead to the adoption of the gold standard (rather than the dual gold and silver standard) in 1816 and a complete recoinage of the nation's gold and silver (and later copper) coins.