What is "balkenkreuz"

The Balkenkreuz is a straight-armed cross that was the emblem of the Wehrmacht (German Armed Forces) and its branches in World War II. It was used by the Heer (Army), Luftwaffe (Air Force), and Kriegsmarine (Navy).

German Balken means "beam, bar", so a literal translation of Balkenkreuz would be "beam cross" or "bar cross".