<Table> <Tr> <Th> Years </Th> <Th> Material </Th> <Th> Weight ( grains ) </Th> <Th> Weight ( grams ) </Th> </Tr> <Tr> <Td> 1793 -- 1795 </Td> <Td> ~ 100 % copper </Td> <Td> 208 grains </Td> <Td> 13.48 </Td> </Tr> <Tr> <Td> 1795 -- 1857 </Td> <Td> ~ 100 % copper </Td> <Td> 168 grains </Td> <Td> 10.89 </Td> </Tr> <Tr> <Td> 1856 -- 1864 </Td> <Td> 88 % copper , 12 % nickel ( also known as NS - 12 ) </Td> <Td> 72 grains </Td> <Td> 4.67 </Td> </Tr> <Tr> <Td> 1864 -- 1942 </Td> <Td> bronze ( 95 % copper , 5 % tin and zinc ) </Td> <Td> 48 grains </Td> <Td> 3.11 </Td> </Tr> <Tr> <Td> 1943 </Td> <Td> zinc - coated steel ( also known as 1943 steel cent ) </Td> <Td> 42 grains </Td> <Td> 2.72 </Td> </Tr> <Tr> <Td> 1944 -- 1946 </Td> <Td> brass ( shell case copper ) ( 95 % copper , 5 % zinc ) </Td> <Td> 48 grains </Td> <Td> 3.11 </Td> </Tr> <Tr> <Td> 1947 -- 1962 </Td> <Td> bronze ( 95 % copper , 5 % tin and zinc ) </Td> <Td> 48 grains </Td> <Td> 3.11 </Td> </Tr> <Tr> <Td> 1962 -- 1981 </Td> <Td> brass ( 95 % copper , 5 % zinc ) </Td> <Td> 48 grains </Td> <Td> 3.11 </Td> </Tr> <Tr> <Td> 1982 </Td> <Td> brass ( 95 % copper , 5 % zinc ) </Td> <Td> 48 grains </Td> <Td> 3.11 </Td> </Tr> <Tr> <Td> copper - plated zinc ( 97.5 % zinc , 2.5 % copper ) </Td> <Td> 38.6 grains </Td> <Td> 2.5 </Td> </Tr> <Tr> <Td> 1983 -- present </Td> <Td> copper - plated zinc ( 97.5 % zinc , 2.5 % copper ) </Td> <Td> 38.6 grains </Td> <Td> 2.5 </Td> </Tr> </Table>
when did they start adding zinc to pennies
1864 -- 1942