Pitches: Eight standard axial pitches have been established to provide adequate coverageof the pitch range normally required: 0.030, 0.040, 0.050, 0.065, 0.080, 0.100, 0.130, and0.160 inch. Lead Angles: There are Fifteen standard lead angles: 0. ANSI B6.9 P = Circular pitch of wormgear P = axial pitch of the worm P x, = in the central plane P x = Axial pitch of worm P n = Normal circular pitch of worm and wormgear = Px cos λ = P cos ψ λ = Lead angle of worm ψ = Helix angle of wormgear n = Number of threads in worm N =Number of teeth in wormgear N = nm G m G = Ratio of gearing = N / n l = lead of a worm which is the distance any one thread advances in a single revolution.
Related Resources: Worm and WormGear Design Equations and Calculator Equations for American Standard Fine Pitch Worms and Wormgears Per.
