A band saw blade consists of a toothed steel loop welded at the ends, moving on two encased wheels, which provide a continuous cutting edge. Home shop models have blades ranging from 1/8 inch to ¾ inch wide. Narrower blades are designed for cutting tight radius curves, while the wider blades are used for making more straight cuts. The teeth of the blades have a spacing of from 6 to 24 teeth per inch (called the pitch). Finer pitches are intended for cutting metals, and the larger pitches are good for cutting large sections of lumber.
Saw Tooth Shapes
The saw blade teeth also can have different shapes. Regular, skip tooth, hook tooth and alternate set types are available. Typical woodworking band saw blades has teeth which are set alternately to the left and right side of the blade, which clear away waste sawdust from the cut efficiently, like a hand saw. Saws for metal work usually have an non-set raker tooth between two set teeth, or wavy set teeth like hack saw blades have.
For cutting plastics and ceramics, blades with no teeth and tungsten carbide chip coatings are available. You can also get these to cut through wood to produce a very smooth finish surface, although the cut will be slow and difficult to work.
Changing a Band Saw Blade
To change a blade on a band saw, you will need to access the two wheels that the blade runs on by opening the wheel guards. You will see that the lower of the two wheels is the one that is driven by the motor. The upper wheel, called the idler wheel, can be adjusted for setting the proper tension on the blade loop, and in some models, for tracking adjustment. In order to protect the blade’s setting, both wheels are rubber-covered.
At the top of the machine, there will be a tension adjustment wheel; turn this until the blade is loose enough to easily lift over both the wheels. Both of the blade guide assemblies should be retracted away from the blade as far as possible, and the table insert with the slot for the blade to pass through should be removed. Now you can remove the old blade.
To fit the new blade, repeat the above steps in reverse. Be sure and install the new blade with teeth facing forward. Depending on your particular model, adjustments to the blade tension, tracking, and guide pins can now be made. Consult the machine operators manual. Guide pins should be adjusted using a feeler gauge to set their clearance with the blade teeth. Turn the saw manually a few turns to check the tension and settings.
Lastly, close both wheel guards and replace the table insert. The height of the upper blade guide assembly is set to the thickness of the work piece, so that it clears the work surface slightly.
Band Saw Blade Care
Blade maintenance involves regular cleanings to remove accumulated dust and shavings. To store blades not in use, they should be either hung from a rack in a loop, or folded in a coil shape. To fold a blade, hold the band about a third up from the bottom of the loop, the teeth facing away from you. Now cross the band to form three loops, left over right.
See Also: How to Sharpen a Hand Saw