It is one of the most used and antique saws, already defined, according to its features, in the Roman era. It is characterized by a blade mounted on a frame, consisting of a central piece called a tightener, and on the side opposite from the blade, by a double twisted rope tightened by a wooden latch and attached to two parallel wooden arms (where both the tightener and the blade are mounted). These two arms work as a lever, so that all of the twisting from the cord corresponds to a greater tension of the blade.