Abstract: A method for testing circular saws in which a saw to be tested is mounted for rotation at a controllable speed, a sensor being mounted opposite a surface thereof for determining the distance from the sensor to the surface. The sensor is appropriately calibrated and, when the saw is rotated at selected speeds, the output signal from the sensor is processed so as to provide a time domain response waveform and a frequency domain response waveform therefrom at the selected speeds of rotation. Certain characteristics of the saw's operation, such as the presence of low frequency "wobble" components, the width of the cutting operation, the perpendicularity of the cutting plane of the saw relative to the axis of rotation, and the development, or flatness, of the saw, are determined from the time domain and frequency domain responses.