How chips are generated
If you will take a good look at the metal teeth of the blades you will see them penetrating the work piece and actually shearing or pushing a continuous chip of metal. The angle by which material is sheared off is called the shear plane angle which is the most important factor in achieving maximum cutting efficiency. With the given depth of penetration, the lower the shear angle plate, the thicker will be chip formation which lowers the cutting efficiency. The higher the shear angel plate, the higher will be the cutting efficiency since thinner chips will be formed. On the other hand, shear plate angle is impacted by different factors like the material of the work piece, band speed, feed, lubrication and blade design.
Feed is the blade’s tooth depth of penetration on the material that is being cut. In order to achieve the most cost effective cutting, it is important to remove as much material in the shortest time possible through a high feed rate and pressure that the metal cutting band saw can handle. However, feed is also impacted by the machinability of the material and the blade’s life expectancy. If cutting is done faster, the blade’s life will be reduced dramatically. To know whether you are using the right feed rate, check the chips, their color and shapes.
Gullet capacity of the metal cutting band saw is another factor that affects cutting efficiency. The gullet is described as the space between the tooth tip and the inner surface of the blade. During the process of cutting, the tooth scrapes away material and chips result. A blade with a proper clearance for the cut will allow chips that curl up uniformly and will fall away from the gullet. If too much material will be scraped off, the chips will jam in the gullet area that cause increased resistance. This will result into wasted energy and damage to the blade.
This is the rate at which the blade cuts across the face of the material that is being cut. More efficient cutting can be achieved if a fast band speed achieves a more desirable shear plane angle. How do you know that you are using the right band speed? The chips will tell you through their shape and color. The main objective is to generate chips that are thin, tightly curled and warm to the touch. If the chips that are generated are golden brown, you are forcing the cut and creating too much heat. Once blue chips are generated, extreme heat is being created that can damage the blades.