SAW, an instrument which serves to cut into pieces several solid matters, as wood, stone, ivory, &c. The best saws are of tempered steel ground bright and smooth: those of iron are only hammer-hardened: hence, the first, besides their being stiffer, are likewise found smoother than the last.
They are known to be well hammered by the stiff bending of the blade; and to be well and evenly ground, by their bending equally in a bow. The edge in which are the teeth is always thicker than the back, because the back is to follow the edge.
The teeth are cut and sharpened with a triangular file, the blade of the saw being first fixed in a whetting block. After they have been filed the teeth are set, that is, turned out of the right line, that they may make the fissure the wider, that the back may follow the better. The teeth are always set ranker for coarse cheap stuff than for hard and fine, because the ranker the teeth are set the more stuff is lost in the kerf.
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