The Main Features Of The Rack

The main features of the rack

(1) Since the tooth profile of the rack is a straight line, each point on the tooth profile has the same pressure angle, which is equal to the inclination angle of the tooth profile. This angle is called the tooth profile angle, and the standard value is 20°.

(2) Any straight line parallel to the addendum line has the same pitch and module.

(3) The straight line parallel to the tooth top line and the tooth thickness equal to the tooth slot width is called the index line (midline), which is the reference line for calculating the rack size.