Generally used is divided into fine teeth, middle teeth, large teeth. The best way to distinguish is to measure the distance between the next two larger teeth with a Caliper, measured in millimeters, divided by 25.4(millimeters in inches), and then measure the distance between the two smaller teeth or by 25.4; There is a ratio between these two figures, the legendary 2/3 tooth, 3/4 tooth, 4/6 tooth saw blade. Or 0.75 / 1.25, 1.0 / 1.6, etc.. The tooth shape also has the angle distinction, 0 °, 6 °, 10 ° etc.. There are also anti-tooth saws, T-tooth saws, and so on, each factory's products have different characteristics.