Читать книгу The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking - Paul N. Hasluck - Страница 99

It should be borne in mind that the workman who can saw squarely to a line is at least two hours a week ahead of one who, either because his saws are in bad order or because he has never got out of the bad habit of sawing out of square, cannot do it. It may be partly, or altogether, the fault of the saw. If one row of teeth is longer than the other, the longer side must of necessity advance faster than the shorter, and constantly tend to force the saw away from the line. The user, in his endeavour, by main force, to compel the saw to follow the line—that is, by twisting that part of the saw which is for the time being above the wood—cannot yet force the bottom half of the saw, which has to follow the direction given to it by the set of the teeth, and consequently the saw is said to “run.” This continues, and the amount it runs from a square cut is doubled, so that, if the stuff has to be planed square and the saw runs only 1/8 in. in 2 in., this implies that 1/4 in. has to be planed away before the edges can be got to fit the square. This wastes both time and material.

Fig. 294.—Obtaining Correct Bevel of Saw Teeth.