Nail (fastener)

In woodworking and construction, a nail is a small object made of metal (or wood, called a tree nail or "trunnel") which is used as a fastener, as a peg to hang something, or sometimes as a decoration. Generally, 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. The history of the nail is divided roughly into three distinct periods: Hand-wrought (forged) nail (pre-history until 19th century) Cut nail (roughly 1800 to 1914) Wire nail (roughly 1860 to the present) 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. The Bible provides a number of references to nails, including the story in Judges of Jael the wife of Heber, who drives a nail (or tent-peg) 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 informal medium of exchange. Until around 1800 artisans known as nailers or nailors made nails by hand – note the surname Naylor.