saw, Tool for cutting solid materials to prescribed lengths or shapes. Most saws take the form of a thin metal strip with teeth on one edge or a thin metal disk with teeth on the edge. The teeth are usually set to alternate sides so that the kerf (groove) cut by the saw is wider than the thickness of the saw; the saw blade can thus move freely in the groove without binding. Thin-strip saws are used in various ways in both hand and machine operations; circular, or disk, saws are always machine powered (see sawing machine, machine tool).