There is a very great number of kinds of nails -about 300 - and only a few can possibly be described here - indeed, it would be beyond the compass and object of this work to endeavour to do more. Briefly, all nails are made to break through the fibres of wood, and are held tightly by the elastic fibres, which, endeavouring to regain their original position, press tightly on the wedge-shaped nail. The tops of nails are variously flattened out into heads, which assist very much in holding them in position, especially if there is any pulling strain at the opposite ends.

The nails recommended for the manual training room, and which will be necessary for constructing the models in the Course, are the following : -

Cat Clasp Nails

(fig. 29). These nails are cut by machinery from a rolled sheet of iron. The head is not very large, and when driven home with the hammer, the slightly projecting top of the head is driven just below the surface of the wood with the hammer and punch. These are typical of a large class of old-fashioned nails, which are, however, gradually being beaten in the market by the newer serrated steel brads.

A similar nail is the Wrought Clasp Nail (fig. 30). This nail is very strong, and the shape of the head gives it a better hold than that of the cut clasp nail. Owing to its fibrous nature it is much used where it is required to clench a nail by bending the projecting point on the reverse side of the piece of work.

Fig. 29.

For the light work of the exercises of a manual training room the best kind is the Oval Steel Brad (fig. 31).

This nail, it will be seen, has slight shallow cannelures round it, near the head. These assist greatly in holding the nail in, and the flat head does not project so much as in the cut nails. The sharp points and oval shape of these nails make them very handy, as they rarely split the wood, and when boring has to be resorted to, a very small hole is necessary.

Fig. 30.

Fig. 31.

Fig. 32.