Nail (0. Eng. naegal, cf. Dutch, Ger., Swed. nagel; the word is also related to Lat. unguis, Gr. 6vu, Sans. nakhas) a word applied both to the horny covering to the upper surface of the extremities of the fingers and toes of man and the Quadrumana (see Skin and Dermal Skeleton), and also to a headed pin or spike of metal, commonly of iron. The principal use of nails is in woodwork (joinery and carpentery), but they are also employed in numerous other trades. Size, form of head, nature of point, and special uses all give names to different classes of nails. Thus we have tacks, sprigs and brads for very small nails; rose, clasp and clout, according to the form of head; and flat points or sharp points according to the taper of the spike. According to the method of manufacture nails fall into four principal classes: (I) hand-wrought nails; (2) machine-wrought and cut nails; (3) wire or French nails; and (4) cast nails.
The nailer handicraft was formerly a great industry in the country around Birmingham. The nails are forged from nailrods heated in a small smith's hearth, hammered on an anvil, the nail length cut off on a chisel and the head formed by dropping the spike into a hole in a "bolster" of steel, from which enough of the spike is left projecting to form the head. In the case of clasp nails the head is formed with two strokes of the hammer, while rose nails require four. The heads of the larger-sized nails are made with, an "oliver" or mechanical hammer, and for ornamental or stamped heads "swages" or dies are employed. The conditions of life and labour among the hand nailers in England were exceedingly unsatisfactory: married women and young children of both sexes working long hours in small filthy sheds attached to their dwellings; their employment was controlled by middle-men or nail-masters, who supplied them with the nail-rods and paid for work done, sometimes in money and sometimes in kind on the truck system. Machine-wrought and cut nails have supplanted most corresponding kinds of hand-made nails. Horse nails are still made by hand-labour. These are made from the finest Swedish charcoal iron, hammered out to a sharp point. They must be tough and homogeneous throughout, so that there may be no danger of their breaking over and leaving portions in the hoof.
In 1617 Sir D. Bulmer devised a machine for cutting nail-rods, and in 1790 T. Clifford patented a device for shaping the rods, but the credit of perfecting machinery mainly belongs to American enterprise (the first American patent appears to be that of Ezekiel Reed, dated 1786). The machine, fed with heated (to black heat only) strips of metal, usually mild steel, having a breadth and thickness sufficient for the nail to be made, shears off by its slicer the "nail blank," which, falling down, is firmly clutched at the neck till a heading die strikes against its upper end and forms the head, the completed nail passing out through an inclined shoot. In large nails the taper of the shank and point is secured by the sectional form to which the strips are rolled; brads, sprigs and small nails, on the other hand, are cut from uniform strips in an angular direction from head to point, the strip being turned over after each blank is cut so that the points and heads are taken from opposite sides alternately, and a uniform taper on two opposite sides of the nail, from head to point, is secured. The machines turn out nails with wonderful rapidity, varying with the size of the nails produced from about 100 to 1000 per minute. Wire or French nails are made from round wire, which is unwound, straightened, cut into lengths and headed by a machine either by intermittent blows or by pressure, but the pointing is accomplished by the pressure of dies. Cast nails, which are cast in sand moulds by the ordinary process, are used principally for horticultural purposes, and the hob-nails or tackets of shoemakers are also cast.
See Peter Barlow, Encyclopaedia of Arts, Manufactures and Machinery (1848); Bucknall Smith, Wire, Its Manufacture and Uses (New York, 1891).
