A “rotary hammer” (aka rotary hammer drill) is a power tool designed for drilling and chiselling hard materials — concretе, masonry, stone — by combining rotation + a powerful hammering (“percussion”) action.
Unlike a regular hammer-drill (which uses a cam or clutch to produce hammering), a rotary hammer uses an electro-pneumatic (EP) mechanism: a piston system inside the tool compresses air and drives a “flying piston,” which delivers stronger, more efficient hammer blows to the drill bit.