Worm gear Lead Distance from any point on a thread to the corresponding point on the next turn of the same thread, measured parallel to the axis. Linear pitch, p Distance from any point on a thread to the corresponding point on the adjacent thread, measured parallel to the axis. For a single-thread worm, lead and linear pitch are the same. Lead angle, λ Angle between a tangent to the helix and a plane perpendicular to the axis. Note that the complement of the helix angle is usually given for helical gears. Pitch diameter, dw Same as described earlier in this list. Note that for a worm it is still measured in a plane perpendicular to the gear axis, not a tilted plane. Subscript w denotes the worm, subscript g denotes the gear.
Worm gear Lead Distance from any point on a thread to the corresponding point on the next turn of the same thread, measured parallel to the axis. Linear pitch, p Distance from any point on a thread to the corresponding point on the adjac.ent thread, measured parallel to the axis. For a single-thread worm, lead and linear pitch are the same. Lead angle, λ Angle between a tangent to the helix and a plane perpendicular to the axis. Note that the complement of the helix angle is usually given for helical gears. Pitch diameter, dw Same as described earlier in this list. Note that for a worm it is still measured in a plane perpendicular to the gear axis, not a tilted plane Subscript w denotes the worm, subscript g denotes the gear.