Gear Pressure Angle Gauges 2

one side has 14.5 degree angle, and other has 20, useful for grinding the tool bit. Gear angles are named off of the angle of the side of one tooth, for a full tooth gap, it's double. So 14.5 is 29, same angle as acme thread, so it can be used to grind acme thread cutting tools, and the 20 degree is 40 degrees together.