TPI is defined as the amount of teeth within 1-inch of the blade’s length. The range of TPI for cutting different type of material. *Blades for metalworking should have a high TPI rating, that range from 6 – 24 TPI. *Blades for cutting wood may offer lower TPI from 3 – 6 TPI Based on the type of material you are cutting will also make you decide the TPI range. Cutting soft material like aluminum require fewer teeth (TPI). Whereas, for tough material cutting like steel, you need a TPI within the range of 12 – 18 TPI. Make sure to consult the user manual for setting proper TPI to set for a band saw.