The comparatively high price of wrought nails, owing to tho great amount of manual labour required In making them, and the 'multi• dewy of cast nails as a substitute for them, has led to the introduction of many highly ingenious machines for forming nails by cutting, stamping, or compression, out of plates or rods of rolled iron ; and with such success that, for the ordinary purposes of the carpenter and joiner, cut-nails, varying in size from the smallest tack or brad up to spikes of six inches or more in length, have almost superseded those wrought by hand. The earliest machine for nail-making was that contrived by Mr. French, of Wimberne, Staffordshire, in 1790, in which no material departure was made from the ordinary process of making nails by the hammer ; but labour was saved by working hammers by water-power, so that women and children might perform work which would otherwise have required men. The Americans, so long as the year 1810, possessed a machine which performed the cutting and heading at one operation, with sufficient rapidity to turn out more than 100 nails per minute. In the process now most com monly followed, nails are cut from sheet-iron of suitable thickness.
The sheet is reduced, by cutting transversely, into strips or rilands of a breadth equal to the intended length of the nails. These -strips are then applied to a machine in which a chisel-shaped cutter descends with sufficient force to cut off from tho end of the strip, at each down ward stroke, a narrow piece sufficient to form one nail. As the nails are required to bo of a tapering form, the cutter must be so fixed as to present a slightly oblique angle to the direction in which the strip is pushed into the machine ; and this obliquity must be reversed or varied after each stroke, by means similar to those adopted in comb cutting machinery. If the nails are to be of any of the kinds to which the term nail is specifically applied, as distinguished from brad, the action of the cutter is simply reversed, so as to reduce the strip of iron into long wedge-shaped pieces ; and the pieces thus separated are subse quently headed by pressure or stamping, so as to form finished nails ; but if the nails are to be of the brad kind, the action of the cutters must be so modified as to produce cuts alternately at right and oblique angles with the edges of the strip. Nails of this kind need no subse quent heading, hut are completed by the action of the cutter. In some machines the cutters do not vibrate or vary their position, but the strip of iron is turned after each cut, so as to produce the same effect. Brads are frequently cut out of hoop-iron instead of transverse strips of sheet-iron, as above described.
Many of the machines recently invented effect improvements in the manufacture of cut nails ; while others, intended for wrought nails, are also applicable to the making of bolts, rivets, spikes, nuts, and screw-blanks. The obvious mode of manufacturing these in a rough
way is to forge the heated end of an iron rod, and to fashion the metal with the hammer ; but the machines now employed increase both the accuracy and the rapidity of the manufacture. One of these machines, invented by Mr. Marrow, of Sheerness Dockyard, is so contrived that it may be put in action by means of a pulley placed upon any moving shaft whatever, whether driven by steam or other power. There are hammers, tappets, &c., connected with the forging part of the mecha nism. With one of these machines one man can make sixty half-inch bolts, an inch and a half long, with hexagonal heads, per hour. Mr. Grice's machine, of recent introduction, forms a head on the heated end of an iron rod, converting the rod into a bolt, rivet, spike, or screw blank. The rod is placed, heated end uppermost, in a die, and by the motion of a bed the rod is brought under a heading-machine, which fashions the head by a pair of dies ; another apparatus liberates the bolt or spike ; and provision is made for keeping the dies cool by allowing a stream of water to fall on them. Mr. Ward's machine, also introduced within a year or two, is so contrived as to make two bolts or other articles by one revolution of a driving shaft. The machine is fed with iron rods by an attendant ; and the metal, whether hot or cold, is cut off and then shaped by dies. There are many other bolt making machines now in use, some of which fashion the bolt or rivet while in a vertical position, others while horizontal; but it is not necessary to describe them separately. The expediency of making rivets by machinery has now become manifest, since modern engineer ing, exhibited in such works as the Britannia Bridge and the Great Eastern steam-ship, requires rivets by millions at a time. Of the new patents for cut-nails, such as Bowman's, Coates s, Goose's, Poole's, Frearson's, and others, it may be said generally that they relate to minor improvements of some of the processes already described in this article.
Birmingham and its neighbourhood are the great seat of the nail manufacture ; wrought nails being made in the villages round about, while cut nails, as well as machine-made bolts, rivets, and spikes, are produced in large factories wrought by steam-power. There are esta blishments in Birmingham which produce 40,000,000 cut nails per week each,—enough in a year to encompass the earth if placed end to end. A few years ago it was estimated that 25,000 persons were employed in the manufacture ; and that 6000 tons of nails were ex ported, after supplying the home trade.