Nail (fastener)


In woodworking and construction, a nail is a small object made of metal which is used as a fastener, as a peg to hang something, or sometimes as a decoration. Usually, nails have a sharp point on one end and a flattened head on the other, but headless nails are available. Nails are made in a great variety of forms for specialized purposes. The most common is a wire nail. Other types of nails include pins, tacks, brads, spikes, and cleats.
Nails are typically driven into the workpiece by a hammer or nail gun. A nail holds materials together by friction in the axial direction and shear strength laterally. The point of the nail is also sometimes bent over or clinched after driving to prevent pulling out.

History

The history of the nail is divided roughly into three distinct periods:
  • Hand-wrought nail
  • Cut nail
  • Wire nail
From the late 1700s to the mid-1900s, nail prices fell by a factor of 10; since then nail prices have increased slightly, reflecting in part an upturn in materials prices and a shift toward specialty nails.

Hand wrought

In hand-working of nails, a smith works an approximately conical iron pin tapering to a point. This is then inserted into a nail-header, essentially a plate of iron with a small hole in it. The broad end of the pin is slightly wider than the hole of the nail-header: the smith fits the pin into the hole of the nail-header and then hammers the broad end of the pin. Unable to advance through the hole, the broad end is flattened against the nail-header to create a nail-head. In at least some metalworking traditions, nail-headers might have been identical to draw-plates.
The Bible provides a number of references to nails, including the story in Judges of Jael the wife of Heber, who drives a nail into the temple of a sleeping Canaanite commander; the provision of iron for nails by King David for what would become Solomon's Temple; and in connection with the crucifixion of Jesus Christ.
The Romans made extensive use of nails. The Roman army, for example, left behind seven tons of nails when it evacuated the fortress of Inchtuthil in Perthshire in Scotland in 86 to 87 CE.
The term "penny", as it refers to nails, probably originated in medieval England to describe the price of a hundred nails. Nails themselves were sufficiently valuable and standardized to be used as an impromptu medium of exchange; trading between James Cook's entourage and Tahitians in the later half of the 18th century being a notable example with the absence of metals in Polynesia's volcanic islands until knowledge of the malleable iron came spread following the breaking apart of Jacob Roggeveen's abandoned Afrikaansche Galey wreck by Takapoto islanders in 1722.
Until around 1800 artisans known as nailers or nailors made nails by hand – note the surname Naylor.
At the time of the American Revolution, England was the largest manufacturer of nails in the world. Nails were expensive and difficult to obtain in the American colonies, so that abandoned houses were sometimes deliberately burned down to allow recovery of used nails from the ashes. This became such a problem in Virginia that a law was created to stop people from burning their houses when they moved. Families often had small nail-manufacturing setups in their homes; during bad weather and at night, the entire family might work at making nails for their own use and for barter. Thomas Jefferson wrote in a letter: "In our private pursuits it is a great advantage that every honest employment is deemed honorable. I am myself a nail maker." The growth of the trade in the American colonies was theoretically held back by the prohibition of new slitting mills in America by the Iron Act, though there is no evidence that the Act was actually enforced.
The production of wrought-iron nails continued well into the 19th century, but ultimately was reduced to nails for purposes for which the softer cut nails were unsuitable, including horseshoe nails.

Cut

The slitting mill, introduced to England in 1590, simplified the production of nail rods, but the real first efforts to mechanise the nail-making process itself occurred between 1790 and 1820, initially in England and the United States, when various machines were invented to automate and speed up the process of making nails from bars of wrought iron. Also in Sweden in the early 1700s Christopher Polhem produced a nail cutting machine as part of his automated factory. These nails were known as cut nails because they were produced by cutting iron bars into rods; they were also known as square nails because of their roughly rectangular cross section.
The cut-nail process was patented in the U.S. by Jacob Perkins in 1795 and in England by Joseph Dyer, who set up machinery in Birmingham. The process was designed to cut nails from sheets of iron, while making sure that the fibres of the iron ran down the nails. The Birmingham industry expanded in the following decades, and reached its greatest extent in the 1860s, after which it declined due to competition from wire nails, but continued until the outbreak of World War I.
Cut nails were one of the important factors in the increase in balloon framing beginning in the 1830s and thus the decline of timber framing with wooden joints. Though still used for historical renovations, and for heavy-duty applications, such as attaching boards to masonry walls, cut nails are much less common today than wire nails.
During the time when the settlers were annexing Texas, using the nail. The nail they used was made of wood, cedar, and copper. They made the wooden ones using a form of carving. The copper nails were made from melting copper and shaping it into a nail form.

Wire

Wire nails are formed from wire. Usually coils of wire are drawn through a series of dies to reach a specific diameter, then cut into short rods that are then formed into nails. The nail tip is usually cut by a blade; the head is formed by reshaping the other end of the rod under high pressure. Other dies are used to cut grooves and ridges. Wire nails were also known as "French nails" for their country of origin. Belgian wire nails began to compete in England in 1863. Joseph Henry Nettlefold was making wire nails at Smethwick by 1875. Over the following decades, the nail-making process was almost completely automated. Eventually the industry had machines capable of quickly producing huge numbers of inexpensive nails with little or no human intervention.
With the introduction of cheap wire nails, the use of wrought iron for nail making quickly declined, as more slowly did the production of cut nails. In the United States, in 1892 more steel-wire nails were produced than cut nails. In 1913, 90% of manufactured nails were wire nails. Nails went from being rare and precious to being a cheap mass-produced commodity. Today almost all nails are manufactured from wire, but the term "wire nail" has come to refer to smaller nails, often available in a wider, more precise range of gauges than is typical for larger common and finish nails. Today, many nails are made using the modern rotary principle nail machine, which allows wire feeding, wire cutting and nail head forming to take place in one continuous process of rotating movements.

Materials

Nails were formerly made of bronze or wrought iron and were crafted by blacksmiths and nailors. These crafts people used a heated square iron rod that they forged before they hammered the sides which formed a point. After reheating and cutting off, the blacksmith or nailor inserted the hot nail into an opening and hammered it. Later new ways of making nails were created using machines to shear the nails before wiggling the bar sideways to produce a shank. For example, the Type A cut nails were sheared from an iron bar type guillotine using early machinery. This method was slightly altered until the 1820s when new heads on the nails' ends were pounded via a separate mechanical nail heading machine. In the 1810s, iron bars were flipped over after each stroke while the cutter set was at an angle. Every nail was then sheared off of taper allowing for an automatic grip of each nail which also formed their heads. Type B nails were created this way. In 1886, 10 percent of the nails that were made in the United States were of the soft steel wire variety and by 1892, steel wire nails overtook iron cut nails as the main type of nails that were being produced. In 1913, wire nails were 90 percent of all nails that were produced.
Today's nails are typically made of steel, often dipped or coated to prevent corrosion in harsh conditions or to improve adhesion. Ordinary nails for wood are usually of a soft, low-carbon or "mild" steel. Nails for masonry applications are tempered and have a higher carbon content.

Types

Types of nail include:
  • Aluminium nails – Made of aluminium in many shapes and sizes for use with aluminium architectural metals
  • Box nail – like a common nail but with a thinner shank and head
  • Brads are small, thin, tapered nails with a lip or projection to one side rather than a full head or a small finish nail
  • * Floor brad – flat, tapered and angular, for use in fixing floor boards
  • * Oval brad – Ovals utilize the principles of fracture mechanics to allow nailing without splitting. Highly anisotropic materials like regular wood can easily be wedged apart. Use of an oval perpendicular to the wood's grain cuts the wood fibers rather than wedges them apart, and thus allows fastening without splitting, even close to edges
  • * Panel pins
  • Tacks or Tintacks are short, sharp pointed nails often used with carpet, fabric and paper. Normally cut from sheet steel, the tack is used in upholstery, shoe making and saddle manufacture. The triangular shape of the nail's cross section gives greater grip and less tearing of materials such as cloth and leather compared to a wire nail.
  • * Brass tack – brass tacks are commonly used where corrosion may be an issue, such as furniture where contact with human skin salts will cause corrosion on steel nails
  • * Canoe tack – A clinching nail. The nail point is tapered so that it can be turned back on itself using a clinching iron. It then bites back into the wood from the side opposite the nail's head, forming a rivet-like fastening.
  • * Clench-nails used in building clinker boats.
  • * Shoe tack – A clinching nail for clinching leather and sometimes wood, formerly used for handmade shoes.
  • * Carpet tack
  • * Upholstery tacks – used to attach coverings to furniture
  • * Thumbtack are lightweight pins used to secure paper or cardboard.
  • Casing nails – have a head that is smoothly tapered, in comparison to the "stepped" head of a finish nail. When used to install casing around windows or doors, they allow the wood to be pried off later with minimal damage when repairs are needed, and without the need to dent the face of the casing in order to grab and extract the nail. Once the casing has been removed, the nails can be extracted from the inner frame with any of the usual nail pullers
  • Clout nail – a roofing nail
  • Coil nail – nails designed for use in a pneumatic nail gun assembled in coils
  • Common nail – smooth shank, wire nail with a heavy, flat head. The typical nail for framing
  • Convex head roofing nail – an umbrella shaped head with a rubber gasket for fastening metal roofing, usually with a ring shank
  • Copper nail – nails made of copper for use with copper flashing or slate shingles etc.
  • D-head nail – a common or box nail with part of the head removed for some pneumatic nail guns
  • Double-ended nail – a rare type of nail with points on both ends and the "head" in the middle for joining boards together. See . Similar to a dowel nail but with a head on the shank.
  • Double-headed nail – used for temporary nailing; nails can easily pulled for later disassembly
  • Dowel nail – a double pointed nail without a "head" on the shank, a piece of round steel sharpened on both ends
  • Drywall nail – short, hardened, ring-shank nail with a very thin head
  • Fiber cement nail – a nail for installing fiber cement siding
  • Finish nail – A wire nail with a small head intended to be minimally visible or driven below the wood surface and the hole filled to be invisible
  • Gang nail – a nail plate
  • Hardboard pin – a small nail for fixing hardboard or thin plywood, often with a square shank
  • Horseshoe nail – nails used to hold horseshoes on hoofs
  • Joist hanger nail – special nails rated for use with joist hangers and similar brackets. Sometimes called "Teco nails"
  • Lost-head nail – see finish nail
  • Masonry – lengthwise fluted, hardened nail for use in concrete
  • Oval wire nail – nails with an oval shank
  • Panel pin
  • Gutter spike – Large long nail intended to hold wooden gutters and some metal gutters in place at the bottom edge of a roof
  • Ring shank nail – nails that have ridges circling the shank to provide extra resistance to pulling out
  • Roofing nail – generally a short nail with a broad head used with asphalt shingles, felt paper or the like
  • Screw nail – a nail with a spiral shank - uses including flooring and assembling pallets
  • Shake nail – small headed nails to use for nailing shakes and shingles
  • Sprig – a small nail with either a headless, tapered shank or a square shank with a head on one side. Commonly used by glaziers to fix a glass plane into a wooden frame.
  • Square nail – a cut nail
  • T-head nail – shaped like the letter T
  • Veneer pin
  • Wire nail – a general term for a nail with a round shank. These are sometimes called French nails from their country of invention
  • Wire-weld collated nail – nails held together with slender wires for use in nail guns