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Show USE & CARE OF CUTTING TOOLS 13 GuFflOntGPS 'oil Son By CLARENCE MEACHAM The carpenters hand saw was designed to cut lumber. Since the origin of the tool other building materials have been developed which present some new problems. SomeiOf these materials are handled very well by the hand saw, while others present a more difficult task. PLYWOOD, PARTICLE board, plastic, masonite and sheet rock can all be cut with the hand saw but will dull the saw much faster. Some of these do better with some variations in the teeth. The rip saw has no bevel on the teeth and they act as a series of small chisels. They also have a greater forward pitch so they bite into the wood faster. This is so because it is easier to cut with the grain of the wood and each tooth can remove a larger chip. This, however, produces more sawdust. The teeth are made larger so there is a larger space, or gullet between the teeth to expedite the. removal of this sawdaust. TEETH OF the rip saw should be set or bent outwardly (this one to the left and the next one to the right) so the blade will not bind as the board tries to pinch back together behind the teeth. The crosscut saw is faced with the more difficult task of cutting across the grain of the wood. It will cut slower and produce less sawdust which requires smaller teeth. Each tooth is given less forward pitch so it will cut more like a knife than like a chisel. IT IS also given a front bevel so the sharp edge will be more like a knife, also a back bevel so the top of the tooth will be very fine and sharp. It is also set in such a fashion that the sharp edge and tip of each tooth leans outward. WESTERN Division: one this set is alternated iium one tooth to the next, as is the bevel, thus it cuts a wider groove which precents binding. FROM THE foregoing it should be obvious why the saw should be sharp. This is even more important as we cut some of the newer building build-ing materials. These materials are full of glues and bonding material which dull the saw faster than regular lumber. Sharpness is also a great factor when a very fine smooth cut is required. Finish carpenters also require saws with finer teeth which hold slivering and roughness to a minimum. Normally the finer teeth require less bevel. THE HAND saw should be oiled or waxed (some use ivory soap) so the saw will resist rust and move easily through the wood. Rust will cause the saw to drag and will also cause the saw to become brittle. Brittleness will cause the teeth to break when set and this can only be repaired by retoothing the saw. Rust also makes pits in the saw which effect the sharpness even when resharpened as the pits become part of the sharp edge. SINCE THE sharp fine edge of the teeth are turned outward, the saws should never be laid flat on a hard surface and should be protected pro-tected from kinking and having hav-ing heavy objects dropped on them. Dents and kinks will cause a drag when in use and cause the saw to cut crooked Keep all cutting tools clean dry and sharp if you want to do a craftsman-like job |