A sledgehammer is a large, heavy, long handled hammer used for demolishing walls, breaking concrete or rocks, etc. The hammer has a large, somewhat rounded metal head, though it may angular pieces on the corners. The handle is often about three feet long, made of wood or a high-impact plastics. The sledgehammer is obviously not built for the purpose of use as a weapon in mind, but sledgehammers and other hammers have been used as improvised weapons since ancient times.