For slightly smallerĪngles, there can be two, three or even more threads. The worm can be considered resembling a helical gear with a high helix angle.įor extremely high helix angles, there is one continuous tooth or thread. A high pressure angle is favored and in some applications values as high as 25° and 30° are used.

The standard values apply to the central section of the mesh. Worm tooth dimensions, such as addendum, dedendum, pressure angle, etc., follow the same standards as those for spur and helical gears.