Part 12 (2/2)

[Ill.u.s.tration: Fig. 175. Using a Handscrew to hold a Board at an Angle.]

The _miter-box_, Fig. 180, is a similar device with the addition of a guide for the saw. The _iron miter-box_, Fig. 181, with the saw adjustable to various angles, insures accurate work.

Such tools as _pliers_, Fig. 182, _pincers_, Fig. 183, and _nippers_, Fig. 184, made for gripping iron, are often useful in the woodworking shop. So are various sorts of _wrenches_; as fixed, socketed, adjustable, monkey- and pipe-wrenches.

[Ill.u.s.tration: Fig. 176. Steel-Bar Carpenter's Clamp. a. Steel Bar. b.

Frame. c. Tip. d. Screw. e. Crank. f. Slide. g. Dog.]

[Ill.u.s.tration: Fig. 177. Iron Handscrew, (Carriage-Maker's Clamp).]

[Ill.u.s.tration: Fig. 178. Pinch-Dog.]

B. _Tools for holding other tools._

The _brace_ or _bit-stock_, Fig. 185, holds all sorts of boring tools as well as screwdrivers, dowel-pointers, etc. The simple brace or bit-stock consists of a chuck, a handle, and a k.n.o.b, and is sufficient for ordinary use; but the ratchet-brace enables the user to bore near to surfaces or corners where a complete sweep cannot be made. It is also useful where sufficient power can be applied only at one part of the sweep. By means of pawls which engage in the ratchet-wheel, the bit can be turned in either direction at the will of the user. The size of the brace is indicated by the ”sweep,” that is, the diameter of the circle thru which the swinging handle turns. To insert a bit or other tool, Fig. 186, grasp firmly with one hand the sleeve of the chuck pointing it upward, and revolve the handle with the other hand, uns.c.r.e.w.i.n.g the sleeve until the jaws open enough to admit the whole tang of the bit. Then reverse the motion and the bit will be held tightly in place. Various hand-, breast-, bench-, bow-drills and automatic drills are of use in doing quick work and for boring small holes, Fig. 187.

[Ill.u.s.tration: Fig. 179. Bench-Hook.]

[Ill.u.s.tration: Fig. 180. Miter-Box.]

[Ill.u.s.tration: Fig. 181. Iron Miter-Box.]

The _screwdriver_, Fig. 188, is a sort of holding tool for turning, and so driving screws. Various devices have been tried to prevent the twisting in the handle. This is now practically a.s.sured in various makes. The other important matter in a screwdriver is that the point be of the right temper, so as neither to bend nor to break. If the corners break they can be reground, but care should be taken not to make the angle too obtuse or the driver will slip out of the slot in the screw-head. The bevel should have a long taper. A shop should be equipped with different sizes of screwdrivers to fit the different sizes of screws. Screwdrivers vary in size, the shank ranging in length from 2-1/2” to 18”. A long screwdriver is more powerful than a short one, for the screwdriver is rarely exactly in line with the axis of the screw, but the handle revolves in a circle. This means an increased leverage, so that the longer the screwdriver, the greater the leverage.

[Ill.u.s.tration: Fig. 182. Pliers.]

[Ill.u.s.tration: Fig. 183. Pincers.]

[Ill.u.s.tration: Fig. 184. Nippers.]

[Ill.u.s.tration: Fig. 185. Ratchet-Brace.]

For heavy work, screwdriver-bits, Fig. 189, in a bit-stock are useful, and for quick work, the spiral screwdriver, Fig. 190, and for small work, the ratchet-screwdriver.

7. MEASURING AND MARKING TOOLS.

It is a long step from the time when one inch meant the width of the thumb, and one foot meant the length of the foot, to the measuring of distances and of angles which vary almost infinitesimally. No such accuracy is necessary in measuring wood as in measuring metal, but still there is a considerable variety of tools for this purpose.

[Ill.u.s.tration: Fig. 186. Inserting a Bit in Stock.]

[Ill.u.s.tration: Fig. 187. Hand-Drill.]

[Ill.u.s.tration: Fig. 188. Screwdriver.]

[Ill.u.s.tration: Fig. 189. Screwdriver-Bit.]

[Ill.u.s.tration: Fig. 190. Spiral Screwdriver.]

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