Clamp-plates for planing consists of a couple of thick holdfast plates which are connected together with two or three screw-bolts and nuts. Such plates are required for gripping an object in a manner similar to that of a vice-chuck, and bolts of various lengths are used to suit the thicknesses of the articles to be held between the plates. An object thus held is shown in Fig. 751, and any piece may thus be gripped which is without any projecting ridge, or cannot be put into a vice, or into a vice-chuck. The surfaces of the plates which are

2 H 2 in immediate contact with the piece being held, should be rough, or grooved, to prevent slipping. When the clamp-plates are tightly fastened to the article, the upper edges of the plates afford convenient ledges to receive the paws of any number of holding plates that may be required, in order to keep the work in close contact with the planing-table. Poppets also can be placed if necessary, so that their screw-points shall bite the sides of the clamp-plates, which will fix the object to be planed, and at the same time also tighten the clamps to the object. Instead of using two straight flat plates for clamping, two cap-plates may be used. A cap-plate is represented in Fig. 646, and two connected together with bolts constitute a clamp which is remarkably efficient for firmly gripping objects of all shapes, whether their surfaces are flat or curved.