Lump hammer

Sledgehammers

20 pounds (9.1 kg) and 10 pounds (4.5 kg) sledgehammers
Classification	Hand tool
Used with	Wedge; hammer wrench
Related	War hammer

A sledgehammer is a tool with a large, flat, often metal head, attached to a lever (or handle). The size of its head allows a sledgehammer to apply more force than other hammers of similar size. Along with the mallet, it shares the ability to distribute force over a wide area. This is in contrast to other types of hammers, which concentrate force in a relatively small area.

The word sledgehammer is derived from the Anglo Saxon "slægan", which, in its first sense, means "to strike violently". The English words "slag", "slay", and "slog" are cognates.

The handle can range from 50 centimetres (1 ft 8 in) to a full 1 metre (3 ft 3 in) long, depending on the mass of the head. The head mass is usually 1 to 3 kilograms (2.2 to 6.6 lb). Modern heavy duty sledgehammers come with 10 to 20 pounds (4.5 to 9.1 kg) heads. Sledgehammers usually require two hands and a swinging motion involving the entire torso, in contrast to smaller hammers used for driving in nails. The combination of a long swinging range, and heavy head, increases the force of the resulting impact.

Sledgehammers are often used in destruction work, for breaking through drywall or masonry walls. Sledgehammers are seldom used in modern mining operations, particularly hand steel. Sledgehammers are also used when substantial force is necessary to dislodge a trapped object (often in farm or oil field work), or for fracturing concrete. Another common use is for driving fence posts into the ground. Sledgehammers are used by police forces in raids on property to gain entry by force, commonly through doors. They were and still are commonly used by blacksmiths to shape heavy sections of iron. The British SAS counter terrorist team used sledgehammers to gain access to rooms during the 1980 Iranian Embassy Siege. However, today they use a tool called a "dynamic hammer".