Four kinds of nails are in common use, viz., plate or cut nails, wire nails, clinch nails and wrought nails.
Cut Nails are made from a strip of rolled iron of the thickness that the nail is to be and a little wider than the length of the nail, the fibre of the iron being crossways of the strip. Special machinery cuts the nails out in alternate wedge-shaped slices, after which the heads are stamped on them and the finished nails are dropped into the casks.
Cut nails are made in a variety of shapes to suit special uses. For ordinary use in building three shapes are made - common, finish and casing. Fig. 329 gives the exact size and shape of an 8d. nail of each kind. The common nails are used for rough work, finish nails for finished work and casing nails for flooring, matched ceiling and sometimes tor pine casings, although the heads are rather too large for finish work.
Fig. 329 - 8d. Cut Nails.
Special nails are also made for lathing, slating, shingling, etc.
Wire Nails. - These have of late years become as common as the cut nails, and are sold at about the same price. They are said to be stronger for driving than the cut nails, and not so liable to bend or break, especially when driven into hard woods, and they are also not as liable to split the wood ; for these reasons they are generally pre. ferred by carpenters.
Wire nails are made from wire of the same size as the shank of the nail, by a machine which cuts the wire in even lengths, heads and points them, and also ribs them when desired. Fig. 330 gives full-size engravings of the various styles of wire nails in common use, the same classification in general being used as for the cut nails. It should be noticed that the gauge of the wire and the shape of the head varies in the different varieties, and that some are barbed while others are plain.
Clinch nails are made from annealed cast iron, and are nearly as flexible as the hand-made wrought iron nails. Wrought nails are made by hand from the best wrought iron, and cost about four times as much as the clinch nail. Both of these nails are used only in places where it is desired to turn over the ends of the nails to form a clinch, as in the case of battens or cleats.
Fig. 330.-Wire Nails (Full Sin).
Sizes. - The length of nails is designated by pennies (ds.), which formerly represented the pennyweights of metal in the nail. This designation as to weight no longer holds good, but the designation is still retained and is practically uniform with the various manufacturers, both for cut and wire nails. The weights run from two to sixty pennies, with the lengths given in the following table, the gauge number being for wire nails:
LENGTH OF NAILS.
LENGTH IN INCHES.
NO. TO POUND.*
The length of the various kinds of nails illustrated is the same for the corresponding penny, but the gauge number varies slightly.
Sizes of Nails for Different Classes of Work. - Contractors who value their reputation may be relied upon to use nails of proper size, but unfortunately there are many builders who, for the sake of saving a few cents, will use smaller nails than the work demands, and to insure against this it is well in certain classes of work to specify the sizes which are to be used. For framing, 20, 40 and 6od. nails (or spikes) are used, according to the size of the timber.
For sheathing and roof boarding, under floors and cross bridging, 10d. common nails should be used. For upper floors 10d. floor or casing nails should be used for jointed boards, and 9d. or 10d. for matched flooring, although 8d. are sometimes used. Ceiling is generally put up with 8d. casing nails when $ inch thick, and 6d. nails when thinner stuff is used.
For inside finish 8d. down to 2d. finish nails or brads are used, according to the thickness and size of the mouldings. For pieces exceeding 1 inch in thickness 10d. should be used.
Clapboarding is generally put on with 6d. finish or casing nails ;
♦These quantities vary slightly with different manufacturers
4d nails should be used for shingling and slating, and 3d. for lathing. For slating, galvanized nails should be used, and they are also better for shingling.
Whether wire or cut nails shall be used may generally be left to the builder, but in places where there is any danger of the nails being drawn out either by the warping of the boards or from the strain on the nail, cut nails should be used, as they have much greater holding power than the wire nails.
From comparative tests made at the Watertown Arsenal of the power required to draw nails when driven to their head in spruce timber, it was found that in the whole forty series of tests (each series comprising ten pairs of cut nails and wire nails of one size), comprising forty sizes of nails, the cut nails showed an average superiority in holding power of 60.5 per cent., the common nails showing an average superiority of 47.51 per cent., and the finishing nails an average of 72.22 per cent. In no series of tests did the wire nails hold as much as the cut nails.
Copper and Brass Nails. - Nails are also made of copper and cast brass. They are sometimes used in connection with boat building, refrigerator work, etc. One wing of the Physical Laboratory Building of Harvard College is put together entirely with brass and copper, no iron being used about the construction of the building, as the rooms were intended to be used for delicate electrical work.