The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking. Paul N. Hasluck
show the ordinary kind of saw-set, whilst the one illustrated by Fig. 297 has a gauge attached to it. To use a saw-set, the back of saw is held in the left hand (as A, Fig. 298), or it is gripped in a vice (see Fig. 299), and the handle of the saw-set is taken in the right hand. Then select a notch that easily fits over the tooth, and proceed very carefully to bend alternate teeth towards the body by pressing the handle downwards. Care must be taken to make the pressure equal upon each tooth, or they will be set out of line. The top of the tooth only must be bent, as a (Fig. 300). Should the whole of the tooth be bent, b, it is very likely to break out. Having set the teeth upon each side, glance down the edge to see if the set is true and regular. The forefinger may be run down the blade at the same time to mark any irregularity, which may be at once corrected by bending the faulty tooth in the desired direction. Figs. 301 and 302 fully illustrate this, Fig. 301 being an end view. Care should be taken to pull the tooth over only a very little; it is far easier to give it a little more than to take some off, and with the slighter amount of bending there is less likelihood of breaking off the teeth. A rip saw requires but very little set; a hand saw about a fourth of its own thickness on each side. After setting a saw, lay it flat on a board, then take a file without its handle and slide it down the sides of the teeth, taking care that it leans towards the back of the saw. This will regulate the set, and if a tooth or two is bent over a little too much, it will file off the excess. After this, pass the oilstone down the same way as the file.
Fig. 298.—Setting Saw held in Hand.
Fig. 299.—Setting Saw held in Vice.
Fig. 300.—Set of Saw Teeth.
PATENT SAW-SETS.
Several excellent contrivances are now made for spring-setting, so arranged that all the teeth can readily be set to one line, and when the contrivance is fixed it is impossible to overset a tooth; and should the saw be found to bind at any particular point, the teeth can, with this contrivance, be set into line, and any excessive friction reduced. Fig. 303 illustrates such a set, adapted for setting hand, circular, mill, or band saws. Its operation will be readily understood: Hold the saw C with the teeth upwards; adjust the die B (Fig. 303), by means of the screw A in the end of the set, so that the angle on the die B will come near the root of the tooth on a fine saw; on a coarse saw, the angle of the die should strike the tooth about two-thirds down from the point. Set the guard E on the under side of the set forward to about in. from the die B; then let the set hang loose on the saw. The space between the tooth and the die will then show the amount of set that is being given to the saw. To increase the set, move the guard E still closer to the die; to decrease the set, move the guard back. Many other excellent saw-sets may be obtained at a moderate price.
Figs. 301 and 302.—Testing Set of Saw Teeth.
Fig. 303.—Patent Saw-set in Use.
HAMMER-SETTING SAW TEETH.
The teeth of a hand saw may be hammer-set by securing in a vice a small setting iron, about 6 in. or 7 in. long, shown in end view by Fig. 304. This iron is bevelled at E and F. The saw, of which G is a section, is laid flat on the iron, and tooth H struck with the pene of a small hammer (see Fig. 305), the operator striking every alternate tooth from one side, then every alternate tooth from the other side of the saw plate. Fig. 304 shows bevel E to be somewhat greater than bevel F; the larger teeth are set on bevel E, and the smaller teeth on bevel F. Instead of the block shown by Fig. 304, that illustrated in section by Fig. 306, p. 81, can be employed, but the beginner will prefer the former, as it determines the amount of set. Another device is a steel plate about 6 in. long, with one edge turned over, as at a (Fig. 307); the other edge b is placed in the vice, and the saw c is then laid upon it as shown, being held in position with the left hand. The tooth is then bent over by lightly striking it with the hammer, which bends the tooth to the bevel of plate, as at d (Fig. 308). Another shape of hammer is illustrated by Fig. 309, p. 82, in which pene J is used for setting the coarser teeth and pene K for the finer teeth. Fig. 310 shows a hammer for setting two-handled cross-cut saws, the teeth of which are set in a similar manner to that just described. Fig. 311 shows an end view of the anvil or setting iron, which is larger than that used for a hand saw, and the bevel is longer. L is a section of the saw, and the tooth M comes over the bevel N; every alternate tooth is struck with the poll O of the hammer shown in Fig. 310. Great care is necessary in hammering; never strike the blade of the saw, or it will buckle; this buckling sometimes happens with spring-setting, but in most cases the saw will go back again when setting the opposite side. Saws that are set by the blow of a hammer or punch are apt to be more irregular than spring-set saws; the operation should therefore be very carefully done, and the teeth constantly tried with a gauge or straight-edge, to see that all the teeth are exactly in line. Hammer-set teeth stand well up to their work in cross-grained and knotty wood, whilst spring-set teeth are more inclined to dodge the knots. Some saws have part of the teeth spring-set and part hammer-set, but the difficulty of keeping them exactly uniform neutralises any advantages the plan may possess. Saw teeth are very apt to fracture if given unnecessary set; that is, by trying to get the set from the whole length of the tooth. In connection with this, Disston says that a saw that is easily filed and set is easily made dull, but he dares not make saws as hard as he would like to, until a better method of setting is adopted by the average mechanic, who instead of getting the whole of the set out of the tooth, tries to get part of it from the body of the plate; and, of course, as soon as he gets below the root of the tooth, the saw plate is distorted and strained. This causes a full-tempered saw blade to crack, and ultimately the saw will break at this point.
Fig. 304.—Setting Iron.