The band saw is a power tool designed primarily to cut materials to a required shape or specification. It works by drawing a straight blade over the workpiece using cutting teeth. The band saw cuts each piece with a step or stroke usually starting at the center and proceeding outwards. The band saw can also be referred to as a radial arm saw or a crosscut machine.
Band saw cutting designs a crosscutting pattern or a parallel profile, either of which can be printed on the blade and are known as “running cuts”. Running cuts are generally easier and more efficient in the short run because they do not require the operator to continuously apply pressure while the blade is in operation. Continuous application of pressure requires accuracy, which is impossible to obtain with running cuts. The advantage of continuous running cuts is that they are economical in the long run because they are a closed loop construction and require little machine lubrication. The horizontal band sawing machine also incorporates a horizontal blade with two cutting teeth that are drawn in a downward angle and directed towards the work surface.
The most common materials for the blades are aluminum and sheet metal. An electrical control box is built into the saw blade and contains a number of switches and knobs that control the various sawing actions. In some models, a variable voltage supply is also available. Some band sawing machines use steel ball bearings for the blade tensioning. As the tension increases so does the cost of the unit and the effectiveness of its operation.
Band saw blade tensioners, similar to those used in table saws, use a spring that allows the teeth to rotate gradually. When the blade teeth are almost completely worn down, the tension of the spring will allow the tooth to rotate quickly. This will cause the teeth to catch on each other and push the band down to its original flat position. A band saw motor is required to help drive the saw blades along the fixed path. In addition to this, the motor will need to be powerful enough to rotate the wheels, keep the blades spinning at an appropriate speed, and provide electrical control.
A straight-line sawing machine has no blade guide attachment; it uses the continuous cutting distance as the basis of the distance between the blade and the material being cut. Because this feature eliminates the need for blade movement during the cut, straight-line saws can be used even by inexperienced users because the machine can maintain a consistent accuracy along the length of the blade. The cost of these types of band saw blades is usually very low, which makes them popular for home DIY projects. However, their inability to provide mechanical precision, coupled with their inability to withstand wear and tear, makes straight-line saws unsuitable for use in heavy-duty industrial applications.
Band saws that incorporate both a band and straight blade can be used in combination with either a hacksaw or a table saw. A hacksaw has a table that allows the operator to accurately adjust the feed rate, depth of cut, and width of the piece being cut. On the other hand, a band saw also has a table that can accommodate the operator’s variable needs such as a lower cut rate or a higher one. By combining the straight-line saw with the band saw’s feed rate and depth of cut, the operator can maximize his cutting capacity.