How a saw cuts: kerf width, blade angle and the pull-stroke
Two fragments of mechanical studies; a note reasons about the working of the saw.
The mounted leaf carries dense studies of mechanical parts — screws, clamping jaws and toothed elements — across both fragments. A note in the left column reasons about how a saw works: doubling the width of the cut halves the depth it needs; the teeth should meet at an acute angle in the middle of the blade so that sawdust can escape the kerf; and the saw's force should lie in the pull rather than the push. The two folio sides are otherwise recorded as blank in the transcription, and further untranscribed drawing is visible on both fragments.
On this page
Width against depth of the cut
The note reasons that a doubled width of cut requires only half the depth of that cut, relating the saw's driving effort to how wide its tooth is made.
Kerf angle and the escape of dust
The cutting edge should form an acute angle in the middle of the blade's thickness, so that the material removed can come out of the kerf made in the workpiece.
Cut on the pull, not the push
Leonardo concludes that the force of the saw should always lie in the pulling more than in the pushing.
Screw-and-jaw mechanisms
The two fragments carry studies of clamping devices — screws working against jaws — with toothed detail drawn at the foot of the larger fragment.