Why were pennies in 1944 made with steel?

A popular theory is that some steel coin blanks, or planchets, were left in the hoppers and accidentally distributed. Another possibility is that some planchets for Belgian two-franc coins (which the Philadelphia mint briefly made for the European nation) were accidentally struck with the Lincoln cent dies. read more

Priority was given to war-related needs. Copper was a strategic material since it is used for bullet and shell casings. During 1943, the US substituted steel for copper for the production of all new pennies. These steel pennies proved both less durable and generally unpopular, so by 1944 copper again was being used. read more

The steel planchets used in 1944 were almost certainly leftover from 1943. These are not wrong denomination errors; some steel planchets for U.S. one-cent coins were used in 1944 or very late in 1943 with ‘1944’ dies. read more