Nails are small spikes or pegs of metal, usually of iron, extensively used in building, and generally in the constructive arts. From the immense quantities of nails made in this country, the manufacture may be deemed one of first-rate importance; for, in the neighbourhood of Birmingham alone, upwards of 60,000 persons, men, women, and children, are occupied in their production; and many of the iron-works in the same district furnish from 100 to 200 tons weekly of "split-rods," of the various sizes and qualities required in the making of the nails (see Iron). The workmen who forge the nails are called "nailors;" women, boys, and girls, are likewise employed in the same kind of work; and it is very common to see a whole family working together. Each individual usually confines himself, or herself, to a certain peculiar class of nails, who, consequently, acquires a great degree of expertness and celerity in their production, not to be equalled by those nailors who have been habituated to forge other kinds.

Under the article Forge we have given a drawing and a description of a nailor's forge of the most improved description; we have, therefore, only to notice the other tools employed in the art. These are, a small steel anvil, which is inserted in a massive block of cast-iron; and this latter is usually imbedded in slack, so that the steel anvil only is seen. The hammers used are, of course, proportioned in weight to the size of the nail, and the shapes vary considerably, according to the ideas of the workmen; but they are usually the frustrums of cones, the smaller ends of which constitute their faces; the planes of which are not parallel to the handles, but inclined to them. A nailor keeps constantly several rods in the fire, which he takes up in succession as they become hot, so as not to have to wait for a heat. When the shank of the nail has been drawn out to the required form and length, it is nearly cut off the rod by striking it over a fixed chisel, and is then inserted into the heading tool, from which the rod is then broken off; the nail is then headed in the tool, and turned out of it by turning it upside down, and striking it upon the anvil.

Such is the celerity with which these operations are performed, that there are instances of nailors making as many as 3000 nails, of three inches in length, in a day, and continuing to work at this rate for many days in succession. Every such nail requires, at the least, twenty-five blows of the hammer to form it, besides two or three blasts of the bellows; nevertheless, the work proceeds at the rate of three or four per minute!

In contemporary publications (the London and British Cyclopaedias) we observe it is stated, that the forged wrought-iron nails we have been speaking of have been superseded by the introduction of those made by pressure and percussion in machines. But this statement is extremely incorrect, as every person acquainted with this department of art well knows. The fact is, we believe, that the forged nail manufacture has considerably increased, notwithstanding there is a very great demand for the cut or pressed nails, which are preferred in some few departments of art, on account of their uniformity, and their square points; and in some others, by reason of their greater cheapness than forged nails. It should be understood that there are three leading distinctions of iron nails, as respects the state of the metal from which they are prepared; namely -

1. Wrought, or forged iron nails, being worked out entirely by the hammer from rods, or bars.

2. Cut, or pressed iron nails, which are stamped, or pressed, out of strips of plate-iron.

3. Cast iron nails, in which the metal is melted, and cast in forms of the precise shape of the nails made.

Forged nails are made of three distinct qualities of iron, that is, more or less refined, or tough, according to the purposes for which they are designed. The very best quality is employed for horse-shoe nails, to admit of their being drawn out very fine, and prevent their breaking in the hoof. Wheelwright's nails, which are forcibly nailed against the iron tire, and the clouts, also require the metal to be very tough. In like manner, hurdle-nails require good iron, that the points may clench soundly, and their broad heads not be broken off. The finer or smaller kinds of nails, being much drawn under the hammer, must also be of good iron; and, indeed, all such where great stability is of essential importance. It would, probably, be good policy in the consumer to have all nails made of at least the second best, or medium quality of iron; but the great competition by the manufacturers to render them as cheap as possible, leads to the employment of a very inferior quality of nail rods for making the majority of nails, of which immense quantities are always in demand for the home trade, as well as for exportation to all parts of the world.

Of the wrought, or forged iron nails, there are about 300 sorts, the forms of which are known to the trade by certain specific names, which, for the most part, express the uses to which they are applied; as hurdle, pail, deck, scupper, mop, etc.; but there are others whose applications are so general that they are distinguished by certain technical names, expressive of their form; thus - rose, clasp, diamond, etc, explain the form of their heads, and flat, sharp, spear, etc. their points. The thickness of any specified form is expressed by the terms fine, bastard, strong. The length of some kinds of nails is directly expressed by their lineal measure; but their length is more usually comprehended by the number of pounds or ounces a thousand of them weigh. Thus the simple denomination "7 lb. rose," implies a rose-headed nail with a sharp point, weighing about 7 lbs. to the thousand, and measuring about 1 1/2 inch in length. Now rose nails are made from 1 1/2 to 40lbs. per thousand; in all, about thirty different sizes; and taking the various sizes of other nails (which are not so numerous), we may compute the average number of sizes of each sort at 10, which, multiplied by 300, the number of sorts before mentioned, makes 3000 distinctive names to nails, all of which are immediately and precisely understood by persons engaged in the trade.