A ball-peen (or ball-pein, see Spelling differences; also known in Europe and North America as ball pane) hammer is a type of peening hammer used in metalworking. It is distinguished from a point-peen hammer or chisel-peen hammer by having a spherical or hemispherical peening head. Though the process of peening has become rarer in metal fabrication, the ball-peen hammer remains useful for many tasks such as tapping punches and chisels. The ball-peen hammer should never be used to drive nails, as a claw hammer would, as the head of a ball-peen hammer is made of very tough - but relatively soft - steel, making it ideal for hammering on harder metals. Continual nail hammering with a ball-peen hammer will "dent" and deform its face. The head of a claw hammer is exactly the opposite: It is made of very hard (hence, more brittle) steel, and is designed for hammering relatively soft nails. The two hammers are not interchangeable.