Although “Opener, Can, Hand, Folding” is its official Army nomenclature, it soon acquired the popular name P-38. Historians disagree as to which of three theories explains the moniker. One is that soldiers called it the P-38 because it could open a can faster than the P-38 Lightning fighter plane could fly. A more likely explanation is that the “38″ comes from the length of the can opener, which is 38 millimeters (or 1 1/2 inches). It also is possible that “38″ was the number of punches (a “P” word) it took to open a ration can. All experts agree that P-38 did not derive its name from the Walther P-38 pistol used by the German military in World War II. 

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