A jackhammer is a pneumatic or electro-mechanical tool that combines a hammer directly with a chisel. It was invented by William McReavy, who then sold the patent to Charles Brady King. Hand-held jackhammers are generally powered by compressed air, but some are also powered by electric motors. Larger jackhammers, such as rig-mounted hammers used on construction machinery, are usually hydraulically powered. These tools are typically used to break up rock, pavement, and concrete.
A pneumatic jackhammer
A gasoline-powered breaker on a demolition site
A compressor for running a pneumatic jackhammer
A single-phase demolition breaker
A hammer is a tool, most often a hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nails into wood, to shape metal, or to crush rock. Hammers are used for a wide range of driving, shaping, breaking and non-destructive striking applications. Traditional disciplines include carpentry, blacksmithing, warfare, and percussive musicianship.
A modern claw hammer suited to drive and remove nails
Cartwheel mallets with heads of felt held between steel washers for use with timpani drums
Detail of the head of a war hammer
A geologist's hammer used to break up rocks, as seen in archaeology and prospecting