Band speed is restricted, however, by the machinability of the material and how much heat is produced by the cutting action. Too high a band speed or very hard metals produce excessive heat, resulting in reduced blade life. How do you know if you are using the right band speed? Look at the chips; check their shape and color. The goal is to achieve chips that are thin, tightly curled and warm to the touch. If the chips have changed from silver to golden brown, you are forcing the cut and generating too much heat. Blue chips indicate extreme heat which will shorten blade life.
If you see very fine or pulverized chips, this indicates the blade feed rate should be increased.
If you see thick, heavy or blue-colored chips, your blade is being overloaded.
Loosely coiled chips indicates ideal cutting conditions.