How to Choose the Correct Number of Teeth Per Inch (TPI)

The number of teeth per inch (TPI) is important in obtaining the finish desired and the proper feed rate. A coarse tooth blade (2, 3 TPI) should be used for re-sawing wood and cutting thicker stock up to 8" thick. A fine toothed blade (18 to 32 TPI) should be used for thinner metals and plastics under 1/4". For general cutting of 3/4" plywood 4 TPI will provide a fast cut and 14 TPI will cut much slower but leave a smooth finish on the cut.

When Selecting TPI Remember:

• More TPI gives a smoother but slower cut.
• Fewer TPI allows for a faster cut with a slightly rougher cut surface.
• Should have at least 3 teeth and less than 12 teeth in the work piece.

Bandsaw Blade Thickness

The thickness of a bandsaw blade is determined by the thickness of the blade body. Bandsaw blades vary in thickness .014", .018", .020", .022", .025", .032", .035", .042", .050", .063".
Make sure that you select a blade of proper thickness. The continual flexing of the blade causes metal fatigue and failure of the blade. Fatigue is the tendency of a metal to break under continued flexing.
The thickness of the blade required depends upon the diameter of the wheels and the work to be done. Thick blades will withstand more strain from cutting than thin blades, but will brake more easily from the bending action, especially when run on small wheels. Each revolution flexes the blade to near the elastic limit of the steel, which causes the metal to fatigue and brake quickly. Thinner blades are recommended when the work is light.

This chart offers Guidelines for selecting Blade Thickness for wheel diameters.

It is not always possible to adhere to the above recommendations due to the cutting operation you intend to perform and the particular bandsaw you are using. To maintain extended fatigue life of the blade, select the thinnest blade possible that will offer you the appropriate number to TPI to perform you cutting operation.