Fig. 2106.
By this method, the tool handle is locked to the tool eye by being spread at each end of the same. If the top end of the tool eye were rounded out both ways of the oval, two wedges would be required to spread the handle end to fit the eye, one wedge standing at a right angle to the other. In this case, one wedge may be of wood and one of metal, the one standing across the width of the oval usually being the metal one. The thin edge of the metal wedge is by some twisted, as shown by [Fig. 2106], which causes the wedge to become somewhat locked when driven in.
Fig. 2107.
In fitting the handle, care must be taken that its oval is made to stand true with the oval of the tool eye. Especially is this necessary in the case of a hammer. Suppose, for example, that in [Fig. 2107] the length of the oval of the handle lies in the plane a b, while that of the eye lies in the plane c d, then the face of the hammer will meet the work on one side, and the hammer will wear on one side, as shown in figure at e. If, however, the eye is not true in the hammer, the handle must be fitted true to the body of the hammer; that is to say, to the line c d. The reason for this is that the hand naturally grasps the handle in such a manner that the length of the oval of the handle lies in the plane of the line of motion when striking a blow, and it is obvious that to strike a fair blow the length of the hammer should also stand in the plane of motion.
