684,628,000 were minted at the Philadelphia Mint - http://cointrackers.com/coins/13590/1943-steel-wheat-penny/
Well worn 1943 cent, made from zinc plated steel because copper was a restricted war material and the mint was not allocated sufficient copper by the War Production Board to make cents out of copper. They proved to be unpopular because they were easily confused with dimes when new, and quickly turned ugly in circulation and sometimes developed rust on the edges because the blanks were punched from plated strip and that left the raw steel exposed on the edges.
