The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking. Paul N. Hasluck
angle being so obtuse that it is apparently ill-fitted for dividing fibres. Lastly, the teeth are so sharpened that their outer points first enter the wood, and the fibre is divided by a gradually incisive kind of action. Not one of these points can be neglected with impunity, for they all conduce to the proper operation of the hand saw. Six teeth to the inch are very suitable for a hand saw. This tool is used for the coarser kinds of work, sawing off stuff—especially large stuff—and for use on buildings, trimming joists, and cutting rafters, halving plates together, and other rough jobs; it is not much required in a shop. As a good general tool in a shop, or for fixing work in the interior of a house, a panel saw is much to be preferred. This is a saw about 2 in. or 3 in. shorter, and much narrower, thinner, and lighter than the hand saw. If a panel saw is once taken to for general work, the hand saw will not be much used, except for heavy work. For cutting along the grain (technically known as ripping) is used the rip saw, as by means of its large teeth the work may be accomplished more quickly than with the band saw. The blade is about 28 in. long, and there are three teeth to the inch, these being sharpened square across the blade, and set very much forward. For cutting shoulders, the tenon saw is used, owing to the teeth being finer, thus producing the clean cut which is so desirable for this purpose. Figs. 244 to 246 show three tenon saws, which differ only very slightly from one another. The common tenon saw has more or less both of set and rake, according to the material upon which it is chiefly used. Usually it is set and sharpened in a medium or average style for general bench use. But according to the character of the work mainly done, the size of the saw selected is from the 12-in. or 14-in. tenon to the 6-in. or 8-in. dovetail, the teeth in the latter case being so fine that the thinnest wood and the most delicate joints can be cut without risk of tearing up the grain. As to the proper saws to be used for cutting the parts of joinery, there can be no hard-and-fast rules laid down. A tenon may be so large that it may be formed by cutting with the grain with the rip saw. and across the grain with a panel saw, or so small that a dovetail saw is of ample size for both purposes. Again, a dovetail joint may easily be large enough to warrant the use of a tenon saw, and yet not be so large as dovetails are sometimes required. It is of importance to learn to use the saw so as to require as little as possible the aid of chisels to pare the tenons, etc. It is far more economical of time to cut the work properly at first rather than to trust to the use of chisels to reduce tenons too stout, dovetails too big, sockets too small, or mortises too narrow; and attention is directed to instructions given on p. 83 on the proper use of the saw. The bow saw, turning saw, or frame saw (Fig. 247) is invaluable for cutting out curved work either with or across the grain; for a similar purpose is used the compass or lock saw, of which Figs. 248 to 251 show four kinds. A nest or set of interchangeable saws (Fig. 252) is a boon to the occasional worker.
Fig. 244.—Tenon Saw.
Fig. 245.—Tenon Saw.
Fig. 246.—Tenon Saw.
Fig. 247.—Bow or Frame Saw.
Fig. 248.—Compass Saw.
Fig. 249.—Compass Saw.
Fig. 250.—Compass Saw.
Fig. 251.—Compass Saw.
Fig. 252.—Set of Interchangeable Saws.
Fig. 253.—Rip Saw Teeth.
VARIETIES OF SAW TEETH.
Many workmen think that so long as the tooth of a saw has a sharp edge the shape of the tooth is a matter of small importance, and as a result of this ignorance or indifference they are always in trouble with their saws, and their work becomes much more laborious than if proper attention had been paid to the shape of the teeth. Substances of different texture cannot be cut advantageously with the same tool; in fact, the tool must be adapted to the work if the best all-round results are to be produced. Fig. 253 illustrates a form of tooth suitable for an ordinary hand rip saw. The tooth points number about four to the inch, and the front of the tooth is upright, that is, at an angle of 90°. The face of the tooth should be filed to an angle of 85° to 87°, or 3° to 5° from the square. Some experts contend that the teeth of a rip saw should be filed dead square. The object in filing them a little on the bevel is that the teeth may cut more freely and easily when they have become a bit dull, there being then what is termed a little clearance cut in the teeth. In nearly all timber there is, it is well known, a certain amount of fibre to be cut either directly or obliquely across, and teeth that are filed square will not, whether they are sharp or dull, divide this fibre so easily as teeth that have a slight bevel. Fig. 254 shows a suitable tooth for a hand-saw used for cross-cutting soft wood. The tooth points in this saw may number five or six to the inch. The front of the tooth slopes at an angle of about 105°. The face of the tooth in sharpening should be filed to an angle of from 55° to 60°. The softer the timber that is to be cross-cut, the more acute should be the angle of the teeth, as the keener edge separates the fibres more easily. Fig. 255 shows a form of hand-saw tooth suitable for cross-cutting hard wood. The number of tooth points may be from six to eight to the inch, and the front of the tooth should slope at an angle of 110° to 115°, according to the hardness of the timber to be sawn. The face of this tooth should be the inch, and the front of the tooth should slope at an angle of 110° to 115°, according to the hardness of the timber to be sawn. The face of this tooth should be filed to an angle of 70° to 75°, because the cutting edge must be less acute owing to hard-wood fibres being more compact than those of soft wood. Another form of tooth in a one-way hard-wood cross-cut saw is shown by Fig. 256. If this form of tooth is properly sharpened, it will be found to cut much faster in hard wood than a tooth that cuts both ways. The front of this tooth, as illustrated, slopes at an angle of about 105°. If the wood to be cross-cut is dry and very hard, the teeth should slope at an angle of 110°, or even more. The tooth points of this saw should be about 5/8 in. from point to point, and the face of the tooth should be filed or ground, as the case may be, to an angle of about 70°. The teeth should be parallel with the back edge of the saw, which, in working, should be pulled and pushed perfectly straight. There is not much difference