Yes they do.
No British decimal general circulation coin has any silver content at all.
The "silver" coins of all Commonwealth countries similarly have no silver content.
There have been six King Georges from 1714 to 1952. 1919 and 1920 were the two years when the British silver coinage was debased from 0.9250 to 0.5000 silver. Which year the change was made depends on the denomination of the coin. Prior to 1919/1920, all British "silver" coins had a 92.5% silver content. From 1919/1920 to 1946, all British "silver" coins had a 50% silver content. From 1947 to present, all circulating British "silver" coins had a 0% silver content.
No circulating British "silver" coin has contained any silver at all since 1946. Since 1947, all British "silver" coins been made from a copper-nickel alloy. Queen Elizabeth II coins from the 50 plus British Empire/Commonwealth countries may or may not have had a silver content depending on the country concerned and the year.
The British silver coinage was degraded from 1919/1920 from sterling silver to 50% silver. All British silver coins from 1919/1920 to 1946 inclusive had a 50% silver content. From 1947 onwards, all circulating British "silver" coins were made from a copper-nickel alloy.
All British Halfcrown coins, up to but not including 1920, were made from sterling silver (92.5% silver).
1919 and 1920 were the two years when the British silver coinage was debased from 0.9250 to 0.5000 silver. Which year the change was made depends on the denomination of the coin. Prior to 1919/1920, all British "silver" coins had a 92.5% silver content. From 1919/1920 to 1946, all British "silver" coins had a 50% silver content. From 1947 to present, all circulating British "silver" coins had a 0% silver content.
No British coin has ever been 100% silver. For hundreds of years, British silver coins had a very high proportion of silver in them. From the Great Recoinage Act of 1816, British silver coins were standardised to sterling silver with a 92.5% silver content. The use of sterling silver to mint silver coins continued until 1919/1920 when, due to a sharp increase in the price of silver, British coins were debased to 50% silver. The 50% silver content continued to 1946 when, due to Britains pressing need to repay war loans to the US, the use of silver was discontinued. All British silver coins from 1947 onwards were made from a copper-nickel alloy.
From 1817 until 1919, all British silver coins had a fineness of .925; i.e. 92.5% silver or sterling silver. In 1920 the silver content was reduced to 50%. In 1947, what were silver coins, were subsequently made from a copper/nickel alloy - no silver at all. No circulating British coin has contained any silver since 1946.
Zero. All British "silver" coins from 1947 onwards, were made from a copper-nickel alloy.
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.
No circulating British decimal coin contains any silver at all. The closest you might have got, prior to 1920, to a pure silver circulating coin was 92.5% (sterling silver), the standard at the time. From 1919/1920, the silver content of British coins was reduced from 92.5% to 50%. From 1947, all British "silver" coins contained no silver at all, they were made from a copper-nickel alloy. There are a number of non-circulating British coins minted from time to time, that have a 92.5% silver content.
The silver content of the 1981 British Royal Wedding commemorative general circulation crown is zero. It is a cupro-nickel coin. No British general circulation coin has had any silver content since 1946. The 1981 silver Proof FDC Crown coin which was sold in a case, has a 92.5% silver content.
In 1900, British "gold" coins were made from 22 carat gold (91.67% gold content). These included the whole range of Sovereign coinage. British "silver" coins were made from sterling silver (92.5% silver content). These included the Crown, Halfcrown, Florin, Shilling, Sixpence and Threepence. British "bronze" coins were made from 95% copper, 4% tin and 1% zinc. These included the Penny, Halfpenny and Farthing.