<P> In 1943 , at the peak of World War II , zinc - coated steel cents were made for a short time because of war demands for copper . A few copper cents from 1943 were produced from the 1942 planchets remaining in the bins . Similarly , some 1944 steel cents have been confirmed . From 1944 through 1946 , salvaged ammunition shells made their way into the minting process , and it was not uncommon to see coins featuring streaks of brass or having a considerably darker finish than other issues . </P>
when did they start adding zinc to pennies
1943