What is a Hammer Drill A hammer drill also comes with other names such as roto-drill, rotary hammer and hammering drill, to name a few. It is basically a rotating drill that, at the same time, has a hammering movement. This hammering action of the tool facilitates the rapid and short hammer force or thrust that can drill into a surface with just little effort on the part of the operator. A hammer drill can either be corded or cordless. A corded hammer drill that is powered by electricity would usually entail attachment into an electric outlet. The cordless hammer drill, on the other hand, is powered by a battery – most commonly used is a Lithium-ion battery – and is more portable and compact than the corded type.