Evaluating the Cutting Mechanics of Woodworking Hand-Saw Teeth

The research detailed in this paper investigates the chip formation modes for woodworking handsaw teeth. Two tooth geometries (beveled and un-beveled) were evaluated using a single tooth rig. A high speed video camera was used to observe the chip formation in real time. For both tooth geometries the video footage provides evidence of a shearing mechanism cutting along the wood grain, and a bending mechanism cutting across the wood grain. Un-beveled teeth (with orthogonal edges) generally yield high cutting forces yet are very effective at removing material along the wood grain in a "chisel like" cutting action. Beveled teeth with sharp lateral edges generally yield low cutting forces and are well suited to severing the wood fibers perpendicular to the grain in a "knife like" cutting action.