carpentry, the art and trade of cutting, working, and joining timber. The term includes both structural timberwork in framing and items such as doors, windows, and staircases.

In the past, when buildings were often wholly constructed of timber framing, the carpenter played a considerable part in building construction; along with the mason he was the principal building worker. The scope of the carpenter’s work has altered, however, with the passage of time. Increasing use of concrete and steel construction, especially for floors and roofs, means that the carpenter plays a smaller part in making the framework of buildings, except for houses and small structures. On the other hand, in the construction of temporary formwork and shuttering for concrete building, the carpenter’s work has greatly increased.

Because wood is widely distributed throughout the world, it has been used as a building material for centuries; many of the tools and techniques of carpentry, perfected after the Middle Ages, have changed little since that time. On the other hand, world supplies of wood are shrinking, and the increasing cost of obtaining, finishing, and distributing timber has brought continuing revision in traditional practices. Further, because much traditional construction wastes wood, engineering calculation has supplanted empirical and rule-of-thumb methods. The development of laminated timbers such as plywood, and the practice of prefabrication have simplified and lowered the cost of carpentry.

The framing of houses generally proceeds in one of two ways: in platform (or Western) framing floors are framed separately, story by story; in balloon framing the vertical members (studs) extend the full height of the building from foundation plate to rafter plate. The timber used in the framing is put to various uses. The studs usually measure 1.5 × 3.5 inches (4 × 9 cm; known as a “2 × 4”) and are spaced at regular intervals of 16 inches (41 cm). They are anchored to a horizontal foundation plate at the bottom and a plate at the top, both 2 × 4 timber. Frequently stiffening braces are built between studs at midpoint and are known as noggings. Window and door openings are boxed in with horizontal 2 × 4 lumber called headers at the top and sills at the bottom.

Floors are framed by anchoring 1.5 × 11-inch (4 × 28-centimetre) lumber called joists on the foundation for the first floor and on the plates of upper floors. They are set on edge and placed in parallel rows across the width of the house. Crisscross bracings that help them stay parallel are called herringbone struts. In later stages, a subfloor of planks or plywood is laid across the joists, and on top of this is placed the finished floor—narrower hardwood planks that fit together with tongue-and-groove edges or any variety of covering.

The traditional pitched roof is made from inclined studs or rafters that meet at the peak. For wide roof spans extra support is provided by adding a horizontal cross brace, making the rafters look like the letter A, with a V-shaped diagonal support on the cross bar. Such supports are called trusses. The principal timbers used for framing and most carpentry in general are in the conifer, or softwood, group and include various species of pine, fir, spruce, and cedar. The most commonly used timber species in the United States are Canadian spruces and Douglas fir, British Columbian pine, and western red cedar. Cedar is useful for roofing and siding shingles as well as framing, since it has a natural resistance to weathering and needs no special preservation treatment.

A carpenter’s work may also extend to interior jobs, requiring some of the skills of a joiner. These jobs include making door frames, cabinets, countertops, and assorted molding and trim. Much of the skill involves joining wood inconspicuously for the sake of appearance, as opposed to the joining of unseen structural pieces (see joint).

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The standard hand tools used by a carpenter are hammers, pliers, screwdrivers, and awls for driving and extracting nails, setting screws, and punching guide holes, respectively. Planes are hand-held blades used to reduce and smooth wood surfaces, and chisels are blades that can be hit with a mallet to cut out forms in wood. The crosscut saw cuts across wood grain, and the rip saw cuts with the grain. Tenon and dovetail saws are used to make precise cuts for the indicated joints, and a keyhole saw cuts out holes. The level shows whether a surface is perfectly horizontal or vertical, and the trisquare tests the right angle between adjacent surfaces. These instruments are complemented by the use of power tools.

This article was most recently revised and updated by Amy Tikkanen.

hand tool, any of the implements used by craftspersons in manual operations, such as chopping, chiseling, sawing, filing, or forging. Complementary tools, often needed as auxiliaries to shaping tools, include such implements as the hammer for nailing and the vise for holding. A craftsperson may also use instruments that facilitate accurate measurements: the rule, divider, square, and others. Power tools—usually handheld motor-powered implements such as an electric drill or electric saw—perform many of the old manual operations and as such may be considered hand tools.

A tool is an implement or device used directly upon a piece of material to shape it into a desired form. The earliest known tools, found in 2011 and 2012 in a dry riverbed near Kenya’s Lake Turkana, have been dated to 3.3 million years ago. The present array of tools has as common ancestors the sharpened stones that were the keys to early human survival. Rudely fractured stones, first found and later “made” by hunters who needed a general-purpose tool, were a “knife” of sorts that could also be used to hack, to pound, and to grub. In the course of a vast interval of time, a variety of single-purpose tools came into being. With the twin developments of agriculture and animal domestication, roughly 10,000 years ago, the many demands of a settled way of life led to a higher degree of tool specialization; the identities of the ax, adz, chisel, and saw were clearly established more than 4,000 years ago.

The common denominator of these tools is removal of material from a workpiece, usually by some form of cutting. The presence of a cutting edge is therefore characteristic of most tools, and the principal concern of toolmakers has been the pursuit and creation of improved cutting edges. Tool effectiveness was enhanced enormously by hafting—the fitting of a handle to a piece of sharp stone, which endowed the tool with better control, more energy, or both.

Early history of hand tools

Geological and archaeological aspects

The oldest known tools date from 3.3 million years ago; geologically, this is the middle of the Pliocene Epoch (about 5.3 million to 2.6 million years ago). The Pliocene was succeeded by the Pleistocene Epoch (2.6 million to 11,700 years ago), which terminated with the recession of the last glaciers, when it was supplanted by the Holocene Epoch (11,700 years ago to the present). The Pleistocene and Stone Age are in rough correspondence, for, until the first use of metal, about 5,000 years ago, rock was the principal material of tools and implements.

At first, humans were casual tool users, employing convenient sticks or stones to achieve a purpose and then discarding them. Although humans may have shared this characteristic with some other animals, their differentiation from other animals may have begun with the deliberate making of tools to a plan and for a purpose. A cutting instrument was especially valuable, for, of all carnivorous animals, humans are the only ones not equipped with tearing claws or canine teeth long enough to pierce and rend skin: humans need sharp tools to get through the skin to the meat. Naturally fractured pieces of rock with sharp edges that could cut were the first tools; they were followed by intentionally chipped stones. For archaeologists, the finding of primitive, intentionally made cutting tools indicates and confirms the early presence of humans at a site. Once understood, fire helped shape wooden implements before adequate rock tools were available for the purpose.

Fire was also the basis of metallurgy. When in historic time the powers of water and wind were applied to the daily tasks of grinding grain and raising water, the way to industrialization was opened.

The idea of relating human history to the material from which tools were made dates from 1836 when Christian Jürgensen Thomsen, a Danish archaeologist, was faced with the task of exhibiting an undocumented collection of clearly ancient tools and implements. Thomsen used three categories of materials—stone, bronze, and iron—to represent what he felt had been the ordered succession of technological development. The idea has since been formalized in the designation of a Stone Age, Bronze Age, and Iron Age.

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The three-age system does not apply to the Americas, many Pacific Islands, or Australia, places in which no Bronze Age existed before the native inhabitants were introduced to the products of the Iron Age by European explorers. The Stone Age is still quite real in some remote regions of Australia and South America, and it existed in the New World at the time of Columbus’s first visit. Despite these qualifications, the Stone–Bronze–Iron sequence is of value as a concept in the early history of tools.

The Stone Age was of great duration, having occupied practically all of the Pleistocene Epoch. Copper and bronze appeared more than 5,000 years ago; iron followed in the next millennium or so and as an age includes the present.

The apparently abrupt transition from rock to bronze tends to mask the critical discovery of native metals and their utilitarian use and fails to indicate the significant discoveries of melting and casting. From bronze one can infer the crucial discovery of smelting, the process by which most of the common metals can be recovered from their ores. Smelted copper necessarily preceded bronze, a mixture of copper and tin, the first alloy. Iron came later, when technique, experience, and equipment were able to provide higher temperatures and cope with problems involved with its use.