A claw hammer is a

hammer A hammer is a tool, most often a hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nail (fastener), nails into wood, to sh ...

primarily used in

carpentry Carpentry is a skilled trade and a craft in which the primary work performed is the cutting, shaping and installation of building materials during the construction of buildings, Shipbuilding, ships, timber bridges, concrete formwork, etc. C ...

for driving nails into or pulling them from wood. Historically, a claw hammer has been associated with

woodworking Woodworking is the skill of making items from wood, and includes cabinetry, furniture making, wood carving, joinery, carpentry, and woodturning. History Along with stone, clay and animal parts, wood was one of the first materials worked b ...

, but is also used in general applications. It is not suitable for heavy hammering on metal surfaces (such as in machining work), as the steel of its head is somewhat brittle; the

ball-peen hammer A ball-peen or machinist's hammer, is a type of peening hammer used in metalworking. It has two heads, one flat and the other, called the peen, rounded. It is distinguished from a cross-peen hammer, diagonal-peen hammer, point-peen hammer, or c ...

is more suitable for such metalwork. An early claw hammer is seen in

Albrecht Dürer Albrecht Dürer ( , ;; 21 May 1471 – 6 April 1528),Müller, Peter O. (1993) ''Substantiv-Derivation in Den Schriften Albrecht Dürers'', Walter de Gruyter. . sometimes spelled in English as Durer or Duerer, was a German painter, Old master prin ...

's etching "

Melencolia I ''Melencolia I'' is a large 1514 engraving by the German Renaissance artist Albrecht Dürer. Its central subject is an enigmatic and gloomy winged female figure thought to be a personification of melancholia – melancholy. Holding her head in ...

," dated 1514, halfway up the left side. There are several nails in the lower right corner.

Design

A claw hammer is composed of a metal head and a handle, which historically was made of wood but also may be of steel, fiberglass, or other composite. One side of the head has a poll
Handtools for Trail Work, United States Forest Service with either a smooth or textured surface and used for driving, while the other is formed into a pair of downward curving V-shaped claws and used for most commonly extracting nails from wood. The greater the curve of the claw(s), and longer the handle, the greater the leverage that may be applied.

Types

Claw hammers can be constructed many ways but generally come in one of two forms. The first, and most popular, type of hammer is the two-piece hammer. This hammer is constructed from a forged

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

head with a hole for fixing a handle. One end is made to fit the hole in the hammer head, then a steel wedge is driven into the wood which forces it to expand and secure the hammer head to the handle. Other handle materials include glass fiber and even carbon fiber. Another type of claw hammer is single-piece forged heat-treated

where the head and handle are integral. These hammers often have polymer grips to add to their ergonomics and decrease vibrations when the hammer is used. Another type of claw hammer is the framing hammer. This is an oversized claw hammer used in framing carpentry. The larger and heavier head can decrease the number of blows required to fully drive a nail, minimized further by increased leverage (torque) and head speed generated by longer handles. Framing hammers also characteristically have a checkered "milled" face, which reduces skip-off of the head if the blow is not precisely struck on the nail. The slight indentations left on the wood by the checkered face are considered unimportant in rough carpentry. Framing hammers also have a much straighter claw than regular claw hammers, as the claw is designed more for prying nailed boards apart, rather than removing nails (though its claw can also be used in that capacity). The size of this type of hammer is commonly designated by the weight of its head, which may range from .

References

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Bibliography

*Hazra Choudhary, ''A text book on workshop technology'' Hammers Woodworking hand tools