Fig. 172. Picture-Frame-Vise.
Handscrews, Fig. 173, consist of four parts, the shoulder jaw and the screw jaw, made of maple, and the end spindle and the middle spindle, made of hickory. The parts when broken can be bought separately. Handscrews vary in size from those with jaws four inches long to those with jaws twenty-two inches long. The best kind are oiled so that glue will not adhere to them. In adjusting the jaws, if the handle of the middle spindle is held in one hand, and the handle of the end spindle in the other hand, and both are revolved together, the jaws may be closed or opened evenly, Fig. 174. In use care must be taken to keep the jaws parallel, in order to obtain the greatest pressure and to prevent the spindles from being broken. It is always important to have the jaws press on the work evenly. To secure this, the middle spindle should be tightened first, and then the end spindle. Handscrews are convenient for a great variety of uses, as clamping up glued pieces, holding pieces together temporarily for boring, Fig. 247, [p. 152], holding work at any desired angle in the vise, as for chamfering or beveling, Fig. 175, etc.
Fig. 173. Handscrew.
Fig. 174. Adjusting Handscrew.
Fig. 175. Using a Handscrew to hold a Board at an Angle.
Clamps are made of both wood and iron, the most satisfactory for speed, strength, and durability are steel-bar carpenter clamps, Fig. 176. They vary in length from 1½ ft. to 8 ft. The separate parts are the steel bar A, the cast-iron frame B, the tip C into which fits the screw D, on the other end of which is the crank E, and the slide F with its dog G, which engages in the notches on the bar. Any part, if broken, can be replaced separately.
