(C.) After jointing the saw, be sure that it is properly set. This may be done by a saw set, of which there are several patterns in use; these are all of two types, the hand set (Fig. 90), and the anvil set (Fig. 91). Either of these forms is efficient, but as it is more convenient, the hand set is more commonly used. Do not give the saw too much set, or it will not cut smoothly, but will break the wood badly on the back side of the cut; there is also greater danger of breaking the teeth, and as more wood is cut out, more muscle must be applied. The point of the teeth only should be set, and care should be used that the blade of the saw is not sprung, which will be apt to result from setting the teeth too far from the point.
Fig. 91.—Anvil Saw
Set.
A saw to be used upon green lumber should have coarser teeth and more set than one which is to be used upon thoroughly dry, seasoned wood. A panel saw intended for use upon fine finishing work usually is ground so thin upon the back that it needs little or no set. Some workmen set a saw so heavily that it will do for several filings; while this is satisfactory for a soft saw to be used upon common work, it is not a good plan to treat a fine, hard saw this way, though the latter may be touched up once or twice.
Fig. 92.—Angle of the File
with the Edge of the
Saw.
(D.) In filing, it is important that the file should be carried at the same angle the entire length of both sides of the blade. For a cutting-off saw, the file should be carried at an angle with the side of the blade of from 60° for soft wood to 70° for hard wood, as shown in Fig. 92; and for general work, at an angle about halfway between the two. The file may be carried horizontally, as at aa, Fig. 93, which makes all the teeth of the same size; as at A, Fig. 94; or it may be carried as at bb, Fig. 93, which will make the teeth of the shape shown at B, Fig. 94. The latter method is preferred by many workmen, as it allows the file to run more smoothly, thus lengthening its life a little. There is no difference in the efficiency of the saws filed by these methods, but if filed as at bb, Fig. 93, it is more difficult to keep the teeth of the same size, and to make a good-looking job.
Fig. 93.—Angle of the
File with the Sides
of the Saw.
In filing a cutting-off saw, the top of the file should be held more or less slantingly, as shown in Fig. 95, according to the hook which it is desired that the teeth shall have. The more hook a saw has, the faster it will cut, but the cut will be rougher in proportion. Experience is necessary to discover just the right angles at which the file should be held; after considerable practice, the file will naturally drop into the correct position.