Pick and Choose
December, 2023- Randy Goss, service technician with Wikus Saw Technology Corp., Addison, Illinois, provides tips for selecting the correct band saw blade.
Q: Where is a good place to start when evaluating band saw blades?
A: Blade performance, overall life and price are all factors in deciding which band saw blade is right for the application. Our goal is to achieve the lowest cost per cut. Applications can vary greatly in material grades, sizes and shapes. Because of those variables, there are several blade options to choose from. It’s important to consider the 80/20 rule—make your blade selection based on what material is cut most of the time because most customers do not change blades to ensure the proper teeth-per-inch selection for the material dimensions being cut. The best blade is not necessarily the least expensive, but it’s the one that is best suited to cut efficiently and economically.
Q: Can you explain the importance of tooth tip composition and tooth geometry?
A: The tooth tip must have the following characteristics: Hot hardness, which is the ability to retain hardness under high heat; toughness for better shock resistance against vibration and impact; and wear resistance to withstand abrasion. Wikus’ bimetal offerings are M42, M42 with a hard coating and X3000. Rake angles are available from 0 degrees to 16 degrees. The rake angle plays an important role in the formation of the chip being created in various materials and the aggressiveness of the cut. We also have carbide products available in ferrous and nonferrous cutting grades, coated versions and various rake angles. These have the ability to share chip load due to each of their unique tooth geometries.
Q: What is blade pitch?
A: Pitch is the distance between one tooth tip and the next. Cutting thin sections of material requires a fine pitch (more teeth), and thicker sections require a coarse pitch (fewer teeth). We recommend operators strive for a minimum of three teeth in the cut. Having six to 12 teeth in the cut at any time is optimal. On a constant-pitch blade, the distance from one tooth tip to the next tip, gullet depth and rake angle are uniform throughout the full length. These blades typically are used for general-purpose cutting. A variable-pitch blade has various tooth sizes and gullet depths to reduce noise and vibration when cutting structural sections, tubing and solids. The lowest/highest pitch on the blade is signified by two numbers, for example, 10/14. Stripping the teeth from the blade should be avoided—and it’s one of the most common problems in band sawing. Usually this is due to overload of forces on the blade caused by repeated impacts with the material, especially while cutting structural shapes and bundles.
Q: Are there any other variables to be aware of?
A: Yes. First, there’s equipment condition and type. Keeping equipment well-maintained and vibration-free will ensure accuracy and longer blade life. Blade wear patterns may be a sign that a wheel adjustment is required or guides are worn and causing problems. It’s also important to choose the right coolant for the cutting application. The proper coolant will help improve the cut and also extend the life of the saw blades.
Wikus Saw Technology Corp., 800/369/0447, http://wikussawtech.com
