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A saw is a tool consisting of a tough blade, wire, or chain with a hard toothed edge. It is used to cut through material, most often wood. The cut is made by placing the toothed edge against the material and moving it forcefully forth and less forcefully back or continuously forward. This force may be applied by hand, or powered by steam, water, electricity or other power source. An abrasive saw has a powered circular blade designed to cut through metal. == Terminology == * Heel: The end closest to the handle. * Toe: The end farthest from the handle. * Front: The side with the teeth (the "bottom edge"). * Back: The side opposite the front (the "top edge"). * Teeth: Small, sharp protrusions along the cutting side of the saw. * Gullet: The valley between the points of the teeth. * Fleam: The angle of the faces of the teeth relative to a line perpendicular to the face of the saw. * Rake: The angle of the front face of the tooth relative to a line perpendicular to the length of the saw. Teeth designed to cut with the grain (''ripping'') are generally steeper than teeth designed to cut across the grain (''crosscutting'') * Points per inch (25 mm): The most common measurement of the frequency of teeth on a saw blade. It is taken by setting the tip (or point) of one tooth at the zero point on a ruler, and then counting the number of points between the zero mark and the one-inch mark, inclusive (that is, including both the point at the zero mark and any point that lines up precisely with the one-inch mark). There is always one more point per inch than there are teeth per inch (e.g., a saw with 14 points per inch will have 13 teeth per inch, and a saw with 10 points per inch will have 9 teeth per inch). Some saws do not have the same number of teeth per inch throughout their entire length, but the vast majority do. Those with more teeth per inch at the toe are described as having incremental teeth, in order to make starting the saw cut easier.〔Barley, Simon "British Saws and Saw Makers from c1660, 2014〕 * Teeth per inch: An alternative measurement of the frequency of teeth on a saw blade. Usually abbreviated TPI, as in, "A blade consisting of 18TPI." (points per inch. ) * Kerf: The width of a saw cut, which depends on several factors: the width of the saw blade; the set of the blade's teeth; the amount of wobble created during cutting; and the amount of material pulled out of the sides of the cut. Although the term "kerf" is often used informally, to refer simply to the thickness of the saw blade, or to the width of the set, this can be misleading, because blades with the same thickness and set may create different kerfs. For example, a too-thin blade can cause excessive wobble, creating a wider-than-expected kerf. The kerf created by a given blade can be changed by adjusting the set of its teeth with a tool called a saw tooth setter. *Set: The degree to which the teeth are bent out sideways away from the blade, usually in both directions. In most modern serrated saws, the teeth are set, so that the kerf (the width of the cut) will be wider than the blade itself. This allows the blade to move through the cut easily without ''binding'' (getting stuck). The set may be different depending on the kind of cut the saw is intended to make. For example, a rip saw has a tooth set that is similar to the angle used on a chisel, so that it rips or tears the material apart. A "flush-cutting saw" has no set on one side, so that the saw can be laid flat on a surface and cut along that surface without scratching it. The set of the blade's teeth can be adjusted with a tool called a saw tooth setter. *Abrasive saw: A saw that cuts with an abrasive disc or band, rather than a serrated blade. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「saw」の詳細全文を読む スポンサード リンク
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