Why the correct width matters when choosing band saw blades
Generally, the type of blade will depend on what you will be cutting since narrow blades are more suitable for radius cutting while wider blades are more apt for straight cutting. To measure blade width, measurement starts from the tips of the teeth to the back edge of the blade. One eight inch blades and three sixteenth inch blades are used in cutting very tight radiuses while one fourth inch blades are used for radius cutting. ¼ inch blades are the narrowest blades used by most band saw machines. If a band saw blade that is narrower than ¼ inch is used, general adjustments would have to be made.
The importance of tooth pitch in band saw cutting
Tooth pitch depends on the material that is being cut and the type of cutting that is done. The tooth pitch will determine the finished product that will be produced since a coarse tooth will usually leave a rough finish with a faster cut while a fine tooth will generate a better finish but with a slower cut. Generally, at least 3 teeth must be in the cut at all times. 3tpi or 3 teeth per inch is suitable for fast cutting of thick stock if finish is not that important. 4tpi can also be used for cutting thick stock and it provides a better finish with slower cut. A fine toothed blade of 18 to 32tpi is often used for thinner metals and plastics that are under ¼” to get a fine finish. 6tpi and 10tpi are general purpose tooth pitches that will allow a decent finish in most materials. So as not make a wrong choice with tooth pitch always remember that:
- More TPI gives a smother finish but with a slower cut
- Fewer TPI allows for a faster cut but with a slightly rougher finish
- At least 3 teeth must always be in the cut at all times
Other factors that determine the right tooth pitch
When cutting round or square tubes and pipes it is important to choose the right tooth pitch. Some materials have varying cross sections and wall thickness that will be encountered by the band saw blades. The best choice is usually a variable tooth pitch that allows cutting through a broader range of pipes and square tubing wall thicknesses using one blade. But in instances when the wall thickness varies significantly, more than one tooth pitch may be necessary. A general rule would be to use a coarser tooth pitch for thinner walled materials if the drop rate is reduced and the blade speed in increased slightly.