A jackhammer (pneumatic drill or demolition hammer in British English) is a pneumatic or * THESE ARE NOT PNEUMATIC MACHINES  electro-mechanical tool that combines a hammer directly with a chisel OR MOIL.
 
The effectiveness of the jackhammer is dependent on how much force is applied THESE ARE MEDIUM AIR BREAKERS DUE TO THE LIGHTER WEIGHT AND SMALLER SIZE THESE ARE USED FOR SMALLER BREAKING JOBS to the tool. And it is generally used to like a hammer to break the hard surface or rock in construction works.