thumb|220px|A portable jackhammer being used to break up Pneumatic hose can be seen leading to the compressor on the back of the truck. The operator is using his body weight to increase the effectiveness of the device.]A pneumatic drill or jackhammer is a portable percussive drill powered by compressed air. It is used to drill rock, break up pavement, among other applications. It works similar to a hammer and chisel, by jabbing with its bit, not rotatin