Bosch Rotary hammer

A rotary hammer is a type of power tool meant to drill holes in hard rocky materials like concrete. The tool usually has a chuck in which the drill bit can slide back and forth so that the impacts are transferred to the material better. The strength of the impact is expressed in Joules.

A rotary hammer is able to drill holes in concrete much faster than a hammer drill which has no sliding chuck and much less powerful impacts.

Many tools have different modes to turn off the hammering making them suitable for drilling in softer materials. The tool is then sometimes referred to as combi(nation) hammer. Some tools have a hammer only mode which allows them to be used as a small demolition hammer.

When the rotary hammer has multiple modes it is also sometimes referred to as a multi hammer.