Against the correctness of filing from point to handle may be cited the following objections:
Where a different angle of back is required (it should be remembered that that angle of face should be the same in nearly all cross-cut hand saws, and that angle of back governs angle of point) it will be found very difficult to obtain it without changing the angle of face of the tooth, and as the cutting duty is on the long side of the face, any change is, of course, of great influence. Again, to file from the point of the saw it is necessary to file with the teeth bent toward the operator. This will cause the saw to vibrate or chatter, a thing which not only renders good, clean, even filing impossible, but breaks the teeth off the file.
Fig. 15.
The setting of a saw is an important part of the work in keeping a saw in order, and should be done AFTER the saw has been jointed, and before filing.
The set should be uniform throughout, as the good working of a saw depends nearly as much on this as on the filing. One great mistake is often made in setting a saw, and that is that many try to put the set in the blade instead of in the tooth. The set should not go at the most lower than half the length of the tooth; by going lower it is liable to spring the body of the saw, if not break the tooth out.
Two methods may be given for setting saws. The first, or old method (employed before saw-sets were invented, and still used by old mechanics) is to take a hardwood block, lay the saw on it, and with a nail set and hammer set every other tooth on the side, then turn the blade over and repeat the operation on the teeth missed from the first side. It is needless to make any comment on this method when saw sets can be bought that are absolutely reliable in their operation.
The second method is to use the saw-set. Saw-sets are made in many styles, and can be bought at any hardware store.
Fig. 16.
