PRECISION MEASURING AND GAGING - OD1642 - LESSON 1/TASK 2
(e) Root Circle (RC): The circle formed by the bottoms of the gear
(f) Root Diameter (RD): The distance from one side of the root
circle to the opposite side passing through the center of the gear.
(g) Addendum (ADD): The height of that part of the tooth extending
outside the pitch circle.
GEAR TOOTH VERNIER.
(h) Circular Pitch (CP): The distance from a point on one tooth to
a corresponding point on the next tooth is measured on the pitch circle.