Resawing
Resawing is the process of slicing stock to reduce its thickness, or to produce boards that are thinner than the original workpiece. Figure 33 demonstrates resawing.
The ideal blade for resawing is the widest one the machine can handle, as the wider the blade the better it can hold a straight line.
When resawing thin stock, use a push block, push stick, or similar device to keep your hands away from the blade.
the tip of the tooth. Generally, wider blades are used for ripping or making straight cuts; narrower blades are often used when the part being cut has curves with small radii. When cutting straight lines with a narrow blade, the blade may have a tendency to wander, causing blade lead. (refer to the Blade Lead section in Adjustments).
Pitch
Pitch is measured in "teeth per inch" (TPI). Figure 34 shows blades with different pitches. A fine pitch (more teeth per inch) will cut slower but smoother. A coarse pitch (fewer teeth per inch) will cut rougher but faster. As a rule of thumb, the thicker the workpiece, the coarser will be the blade pitch. If you have to cut a hard or very brittle material, you will probably want to use a blade with a finer pitch in order to get good clean cuts.
General rule: Use a blade that will have no fewer than 6 and no more than 12 teeth in the workpiece at any given time.
Figure 33
Saw Blade Selection
Using the proper blade for the job will increase the operating efficiency of your band saw, help reduce necessary saw maintenance, and improve your productivity. Thus, it is important to follow certain guidelines when selecting a saw blade.
Here are factors to consider when selecting a blade:
The type of material you will be cutting.
The thickness of the workpiece or part.
The features of the workpiece or part, such as bends or curves with small radii.
These factors are important because they involve basic concepts of saw blade design. There are five (5) blade features that are normally changed to meet certain kinds of sawing requirements. They are:
1.width
2.pitch (number of teeth per inch),
3.tooth form (or shape),
4.the "set" of the teeth
5.the blade material itself.
Width
Band saw blades come in different standard widths, measured from the back of the blade to
Figure 34
Shape
Figure 35 shows common types of tooth shape. Tooth shape has an effect on cutting rate, and with few exceptions, the Skip and Hook types are used to obtain higher feed rates when cutting thick workpieces. Variable-tooth blades are also available, which combine features of the other styles.
Figure 35
23
