Electric Screw Driver Power Tool,Ud Screw Driver Kit,Electric Screwdriver Drill Machine SHANGQIU STAR TOOLS CO.,LTD , https://www.loadstartape.com When measuring the odd-numbered cylindrical gears in the field, it is difficult to determine the diameter D (?) of the tip circle, which brings difficulties to the work. To this end, we derived the basic formula for measuring the modulus m based on mathematical calculations. Take a point C (see figure) on the addendum circle, and C is the midpoint of the cross section of the tooth 1, symmetrical to the CD straight line to select two teeth 2, 3, by the vertices A, B and 1 of the 2, 3 teeth Point C constitutes isosceles â–³ ABC,