Hammer drill

A hammer drill is a drill that, as well as turning the bit, gives it small, very rapid forward blows. That hammer action lets it drill brick, stone or concrete, where an ordinary drill barely makes headway.

The locksmith uses it mainly on the building structure: to anchor a door subframe, fix a grille, fit a bolt with its keep set into the wall or put in a door stop. With the hammer action switched off it is also used on metal and wood, for example when fitting rim locks or escutcheons.

On sheet metal or a lock cylinder it is never used with the hammer action on: the bit jumps, breaks or drills a crooked hole. For metal, it is used on rotation only and with a locksmith’s drill bit. If you are interested in reinforcing a door with anchors into the masonry, see door reinforcement.