Types Of Saws
by Rick Oconnell
Types Of Saws; Basic carpentry hand saws for crosscutting or ripping come in two blade pat-terns. Upper edge of straight back pattern, above, can serve as line marker. Skew-backed type, not suited for marking, is preferred by some because saw seems more flexible.
The backsaw, used for joint cutting, has reinforced back edge to keep blade rigid. Typical lengths are 10 to 16 in. A longer version called a miter box saw runs from 22 to 26 in. To cut smoothly, teeth are finer than on crosscut or rip saws.
Coping saws, for cutting small-diameter curves, have spring steel frames with tension adjustment to hold blades taut. Blades are 1/16 to 1/8 in. wide, and from 6 to 6% in. long. The blades mount to face in any direction.
Compass saw has narrow, tapered blade for cutting curves or starting from bored hole. It is similar to the keyhole saw, which was once used to cut keyholes in wooden doors.
The hacksaw, for metal cutting, has a rigid frame that fits blades 8 to 12 in. long. High-speed steel blade mounts with teeth slanted away from handle and is drawn taut by wingnut.
A crosscut saw's performance depends on the quality of the saw and how you use it. In a high-quality crosscut saw, the teeth are usually precision ground to tiny points that cut sharply across the wood fibers. The teeth of a low-priced saw, though the same
shape, are rarely precision-ground.
Quality saws cut faster with the same effort from you. The number of teeth per inch, referred to as points, commonly ranges from 7 to 12. (A saw that has 7 teeth to the inch is called a 7-point saw.) When a saw has a low point number, it cuts fast but leaves a rough surface. High-number saws work more slowly but are smoother-cutting. For average work, 7 or 8 points is usual; for finer work, 10 points. More tips on Types Of Saws
To reduce sawing friction and boost efficiency, alternate teeth are set (bent) outward about 1/4 the blade thickness to opposite sides. This results in a cut slightly wider than blade thickness and lets the saw cut freely. To begin a cut, use the butt portion of the blade near the handle. Use several pulling strokes to make a starting groove. Don't cut on the marked line, but on the waste (throwaway) side.
This minimizes the chance of cutting short. Continue with full strokes for fast cutting and even distribution of tooth wear along the blade. Because the crosscut saw cuts on both the forward and back strokes under its own weight, you only need to apply light pressure in using it. The most efficient cutting angle between the saw's edge and the surface of the work is 45 degrees. More basic carpentry tips and types Of Saws coming in the near future.