Air hammer

From GAWDAwiki

An air hammer is a pneumatic device that uses highly pressurized air to drive a hammer into a work piece several thousand times per second for shaping, scoring or smoothing. Handheld air hammers are connected to air tanks with tubes to supply pressurized air. Chisel tips are used for cutting and scoring, while hammer tips are used for shaping and smoothing.^[1]

References

1. http://www.wisegeek.com/what-is-an-air-hammer.htm