M4 - A3 Sherman tanks military general patton is special. The M4 is medium tank during World War II, the late famous tank, is also the largest number of tanks in World War II production, total output reached 49234 units, the tanks in the late World War II battle, the M4 tanks played a significant role, so in world war history, occupies an important position. On August 19, 1940, the United States began a new tank development work. Military requirements, the 75 mm gun in a traversable turret, the developed code is T6 medium tank, in September 1941, T6 tank shape and was named the M4 Sherman medium tank. M4 was developed on the basis of the M3 tank successfully, thus the M3 and M4, have distinction already, have again contact. Chassis overall arrangement and action part of them are very similar. The big difference on the turret, the M4 tank turret for whole casting turret, circular arc transition and size on the turret is much larger than the M3.