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
Metal spinning attached. In CNC applications, carbide or tool steel cut-off tools are used. The mandrel does not incur excessive forces, as found in other metalworking processes, so it can be made from wood, plastic, or ice. For hard materials or high volume use, the mandrel is usually made of metal. Several operations can be performed in one set-up. Work pieces may have re-entrant profiles and the profile in relation to the center line virtually unrestricted. Forming parameters and part geometry can be altered quickly, at less cost than other metal forming techniques. Tooling and production costs are also comparatively low. Spin