Saw, a tool that cuts solid materials into a specified length or shape. Most saws take the form of a thin metal strip with teeth on one side or a thin metal disk with teeth on the periphery. Usually, the serrations are "set" (curved) to alternate sides so that the cut (groove) cut by the saw is wider than the thickness of the saw. This prevents adhesion between the cutting surface and the side of the saw. Thin band saws are used in various arrangements for manual and machine operation, while circular saws or circular saws are always driven by the machine.
Portable electric circular saw.
Hand tool: saw
The chipped flint knife has irregular edges. It is not a real saw, although it can cut wood fibers and bones...
The hand hacksaw has a U-shaped frame and a saw blade 20 to 30 cm (8 to 12 inches) long, 1.25 cm (0.5 inch) wide and 0.06 cm (0.025 inch) thick. It is used to close the U shape and pass through the Screw adjustment. This kind of saw is one of the most common tools in mechanical workshops and is used to cut solid parts in a vise. Butchers also use this type of saw to cut bones. For cutting curves and other irregular shapes of wood or other materials, the top or jeweler's saw (basically a hacksaw with a deeper U-shaped frame and narrower blade) is very suitable.
The electric jig saw or rolling saw mechanically performs the same irregular cutting as the manual top cover saw. The straight and narrow blade is installed vertically between the pulsating lower shaft and the reciprocating upper shaft, and they move the blade up and down quickly together. Power hacksaws driven by electric motors are indispensable in any general machining shop or tool room; they are most commonly used for cutting metal. The blade is wider and thicker, and the frame is much heavier than a hand hacksaw. The frame carrying the saw blade moves back and forth, cutting in only one direction, and a slight feed pressure or weight will automatically press the saw on the workpiece.
A vertical band saw blade is an endless narrow metal strip with teeth along one edge and runs around two large electric pulleys or wheels mounted on a frame, one directly above the other. The blade passes through the table where the workpiece is placed. The blade has teeth of various sizes, and on most machines, the blade speed can be changed to suit the material being cut.
Among the saws that are neither ring nor disc, the three most commonly used hand saws for carpenters are: longitudinal saws, cross-cut saws, and back saws. The first two roughly triangular blades about 50 cm (20 inches) long and 10 cm (4 inches) wide are at the handle and taper to about 5 cm (2 inches) at the other end. For cutting wood, cross-cutting saws are used for cutting grains. The main difference between saws is the way the teeth are ground. The cutting edge of the serration is at 90° to the blade, like a row of chisels; there are knife-like teeth that are cut across. They are set on alternate sides, and two parallel lines are cut on each side of the incision, so that the wood in the middle Will be broken. The back saw is a cross-cut saw with a rectangular saw blade and a thick steel back plate opposite the teeth; this can keep the blade completely straight. It is usually guided by an accessory that always remains level and keeps it in the correct direction when making angle cuts.
Among the machines that use rotating steel discs with peripheral teeth, the radial arm saw is one of the most useful machines. The motor-driven blades are manually pulled along a horizontally arranged shaft or pipe, called radial arms, which are themselves supported by vertical columns connected to a heavy-duty base. The motor blade unit can freely move back and forth along the arm, and can be adjusted to different heights by the movement of the radial arm on its vertical support. The motor blade unit can also be rotated for angular cutting and tearing cutting. The work is placed on the wooden table at the top of the base, and the motor blade unit is manually moved through it, cutting while walking. The table saw (or fixed circular saw) consists of a circular saw that can be raised and tilted. The circular saw protrudes from a slot on a horizontal metal table. Work on the table can be placed and pushed into contact with the saw. This saw is one of the basic machines in any woodworking workshop; with a blade of sufficient hardness, a table saw can also be used to cut metal strips. For heavy-duty cutting operations, circular saws or cold saws are widely used in steel mills, such as cold drawing plants or where large amounts of bars and shafts are cut. In operation, the saw car slowly feeds the workpiece.
A portable electric circular saw with a blade attached to the motor shaft is probably the most commonly used saw, especially for household handymen. With the right blade, it can cut almost any material-wood, metal, plastic, fiberglass, cement block, slate and brick. It can tear, cut crosswise and cut diagonally on wood. The saber saw is basically a portable jigsaw puzzle that can be moved up and down and can travel up to 2.5 cm (1 inch). It can be torn, cut crosswise and cut at an angle. The portable chain saw almost replaced the woodcutter's axe and the two-person hand saw used to cut trees. It consists of a thin metal frame supporting a steel roller chain with serrations fixed at intervals along its length; the gears are slightly wider than the chain to prevent the chain body from combining with the material being cut.