Rules for Planing to Dimensions

1. True and smooth a broad surface; put on a face mark. This becomes the face side.

Fig. 67.
Fig. 68.
1. Joint (straighten and square) one edge from the face side; put on a face mark. This becomes the face edge
2. Gage to required width from the face edge, and joint to the gage line.
3. Gage to required thickness on both edges from the face side; plane to the gage lines.

5/ Square one end from the face side and face edge.

6. Lay off with knife and square the required length from the squared end; work to the knife line.

The rules just given are the ones used when stock is entirely in the rough or where it is desired to have the surfaces as nearly perfect as possible. While every student should know how, and be able to square up rough stock quickly and accurately, he should understand that modern mill practice makes it unnecessary to use stock entirely in the rough. Most of the lumber used by cabinet makers and carpenters is machine planed, Fig. 119, on two surfaces to stock thicknesses.

The nature of the piece of woodwork that is to be done determines the method to be used in squaring up mill-planed stock. Your instructor will provide specific directions for the order of procedure until you have acquired the ability to see for yourself the correct method to be used.

35. Planing a Chamfer.— Fig. 69 illustrates a good way to lay out a chamfer. A notch in the back end of the gage- < stick holds the pencil in position. Holding pencil in this way, draw lines on face and edge indicating width of the

chamfer. Fig. 70 illustrates the manner of block-planing a chamfer, the piece being held on the bench-hook. Where the piece can be placed in the vise, Fig. 71 illustrates the method of planing a chamfer with one of the larger planes. First, plane the chamfers which are parallel to the grain; then the ends. If the plane-iron is sharp and set shallow, it can be run entirely across without danger of splitting the corners.

Hold the plane parallel to the edge in planing with the grain. Swing it to an angle of about forty-five degrees

in end chamfering, but move it parallel with the edge, and not with the length of the plane. '

The eye will detect inaccuracies in planing. If further test is desired, Fig. 72 illustrates one.

CHAPTER IV.

Boring Tools—Boring.

36. Brace or Bitstock.—Fig. 73 illustrates a common form of brace. This tool is used for holding the various kinds of bits which are used in boring, reaming, etc.

The ratchet brace consists of essentially the same parts but in addition has an attachment which permits of the crank's acting in one direction or the other only. It is a necessity where the crank cannot make an entire revolution, and is very convenient for boring in hard wood or for

To insert a bit, hold the brace firmly with the left hand, revolve the crank until the jaws are opened far enough to- allow the bit tang to pass entirely within so that the ends of the jaws shall grip the round part—the shank of the bit. Still firmly holding the brace, revolve the crank in the opposite direction until the bit is firmly held. Fig. 74.

37. Center Bit.—The old-fashioned center bit, Fig. 75, is still used by carpenters for certain kinds of work. It

has, for the most part, given way to the more modern auger bit.

38. The Auger Bit.—The auger bit, Fig. 76, is used for all ordinary boring in wood. The action of an auger bit is readily understood by referring to Fig. 76. The spur

draws the bit into the wood. The two nibs cut the fibers, after which the lips remove the waste, later to be passed along the twist to the surface.

Auger bits are usually supplied in sets of thirteen, in sizes varying from one-fourth of an inch to one inch, by sixteenths. Drill bits vary by thirty-seconds.

The size of hole that an auger bit will bore can be told by looking at the number on the tang or shank. If a single number, it is the numerator of a fraction whose denominator is sixteen, the fraction referring to the diameter of the hole which the bit will bore.

Exercise care in laying down a bit; it is easily dulled. Do not use a good auger bit where there is any danger of striking nails or other metal.

Auger bits are easily sharpened, a small file being used, but they are more easily spoiled by improper filing, and no student should attempt to sharpen one without having personal direction from his instructor.

1. The Drill Bit; The Gimlet Bit.—The drill bit, Fig. 77, is quite hard and may be used for boring in metal as well as wood. It is easily broken and especial
2. 77. FIG. 78.

care must be taken to hold the brace firmly. Do not try to change the direction of the boring by inclining the brace after the bit has started into the wood.

In boring hard wood or metal, make a "seat" for the point with an awl, or in metal with a center punch. Otherwise it is difficult to start the bit in the exact place.

The gimlet bit, Fig. 78, is used mainly for boring holes for screws. Diameters vary by thirty-seconds of an inch.

40. Countersink Bit.—Fig. 79 is an illustration of a rosehead countersink. This tool is used for enlarging

screw holes made with the gimlet so that the heads of the screws may sink into the wood even with or below the surface.

41. The Screwdriver Bit.—The screwdriver bit, Fig. 80, is not a boring tool, but as it is used in connection