A ball-peen or ball pein hammer, also known as a machinist's hammer, is a type of peening hammer used in metalworking. It has two heads, one flat and the other, called the peen, rounded.
Ball Peen Hammer is used for light tapping and hard striking purposes while punching, bending, straightening, chipping, forging, riveting and planishing.
Ball Peen hammers is used for forming a rivet head by spreading the shank of the rivet