10 pounds (4.5 kg) and 20 pounds (9.1 kg) sledgehammers |
|
| Other names | Sledge Hammer |
|---|---|
| Classification | Hand tool |
| Used with | Wedge; Hammer wrench |
| Related | War hammer |
A sledgehammer is a tool consisting of a large, flat head attached to a lever (or handle). The head is typically made of metal. The sledgehammer can apply more impulse than other hammers, due to its large size. Along with the mallet, it shares the ability to distribute force over a wide area. This is in contrast to other types of hammer, which concentrate force in a relatively small area.
Contents |
The word sledgehammer is derived from the Anglo Saxon "Slaegan", which, in its first sense, signifies "to strike violently". The English words "slay" and "slog" are both cognate. [1]
The handle can range from 0.5 metres (1 ft 8 in) to a full 1 metre (3 ft 3 in) long, depending on the mass of the head.[2] 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, increase 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 sledge hammers to gain access to rooms during the 1980 Iranian Embassy Siege. However, today they use a tool called a "dynamic hammer."
Another iconic use of sledgehammers is for driving railroad spikes into wooden sleepers during rail construction. When the two ends of the Union Pacific railroad were joined at Promontory, Utah, Leland Stanford hammered a golden spike into a tie with a silver hammer.
Post mauls are similar to sledgehammers in shape, but are meant to drive wooden fence posts into the earth. They have broad, flat circular faces that are significantly larger in diameter than the body of the head (where the handle attaches). Sledgehammers usually have octagonal faces that are the same diameter or slightly smaller than the body of the head.