Its efficiency depends upon (1) the narrowness of the saw cut or "kerf," and (2) upon the force required to drive it thru the material.

The thinner the blade, the less material will be cut out and wasted, and the less force will have to be applied.

In order to have the saw as thin as possible, almost all the people of the world, except the Anglo Saxons, have saws that cut when they are pulled toward the worker.

The blade is in tension while cutting and in compression only when being returned for a new cut.

German carpenters use a saw like our turning-saw.