Lead angle
Description
Lead is the axial advance of a helix or screw during one complete turn (360°). The lead for a screw thread is the axial travel for a single revolution. Pitch is defined as the axial distance between adjacent threads on a helix or screw.
Lead angle is the angle between the helix and a plane of rotation.
Variables
| La | Lead angle (rad) |
| l | Lead of the helix (cm) |
| π | pi |
| dm | Mean diameter of the helix (cm) |