A Device For Every Job - About The Hammer Drill Regular cordless and electrical drills are indispensable devices for use from the home to the job site, but they are not equipped for exhausting jobs such as drilling through granite, concrete or masonry. Hammer drills and rotary hammers are developed for drilling through these more difficult products. Both hammer drills and rotary hammers incorporate the pounding action of a hammer with the rotation of a drill to make penetrating hard, weak surface areas possible. The rotary hammer is the hammer drill's heavier duty equivalent that can carry out more demanding drilling jobs.