Module Pressure Angle 5 20' 405 20' 4 20' 3.75 20' 3.5 20' 3.25 20' 3 20' 2.75 20' 2.5 20' 2.25 20' 2 20' 1.75 20' 1.5 20' 1.25 20' 1 20' 3.25 14.1/2' 0.75 14.1/2'