1943 steel cent coins. The copper cents differ from their steel counterparts in four ways: In an error similar to the 1943 cents, a few 1944 cents were struck on steel planchets left over from 1943. There are two explanations given for why this happened. One explanation is that steel planchets were left in the press hopper and press machines from the previous year mixed in with copper planchets. Another explanation credits the error to the production of 25 million Belgian two franc pieces by the Philadelphia mint after that country's liberation from the Nazis. These coins were of the same composition and
Sheet metal Sheet metal Sheet metal is metal formed by an industrial process into thin, flat pieces. Sheet metal is one of the fundamental forms used in metalworking and it can be cut and bent into a variety of shapes. Countless everyday objects are fabricated from sheet metal. Thicknesses can vary significantly; extremely thin sheets are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate steel or "structural steel." Sheet metal is available in flat pieces or coiled strips. The coils are formed by running a continuous sheet of metal through a roll slitter. In most