Saw

Saw, cutting tool consisting of a flat blade or circular disk, having on its edge a row of sharp teeth of various designs, usually set alternately. The first true saws (copper and bronze) were used in Egypt c.4000 B.C., but only with the use of steel did they become efficient. Hand saws include the crosscut saw for cutting wood to length, the backsaw for joints, the coping saw for shaping, and the hacksaw for cutting metal. Power saws include circular saws, band saws (with a flexible endless steel band running over pulleys), and chain saws.