A ball pein hammer, also known as a ball-peen hammer or machinist's hammer, is a type of hammer that is primarily used for shaping metal or other hard materials. It consists of two primary parts: the head and the handle.The head of a ball pein hammer is made of steel and has a flat surface on one end for striking and a rounded, ball-shaped surface on the other end. The ball-shaped end is typically used for shaping or forming metal, while the flat end is used for striking punches or chisels.