• Common abbreviations
  • n.  Rotational velocity. (Measured, for example, in r.p.m.)
  • ω  Angular velocity. (Radians per unit time.) (1 r.p.m. = π/30 radians per second.)
  • N.  Number of teeth.
     
• Addendum (a)
   
• Angle of action
   
• Arc of action
   
• Axis
   
• Backlash
   
• Base circle
   
• Base pitch (p_b), also called normal pitch
   
• Circular pitch (p)
   
• Clearance
   
• Dedendum (b)
   
• Diametral pitch (P_d)
   
• Helical Gears:
  • Helix angle (ψ)
  • Normal circular pitch (p_n)
  • Transverse circular pitch (p)
     
• Interchangeable set
   
• Interference
   
• Line of action, also called Pressure line
   
• normal pitch (p_b), also called Base pitch
   
• Outside diameter (D_o)
   
• Path of contact
   
• Pitch circle, also called Pitch line
   
• Pitch diameter (D)
   
• Pitch point (p)
   
• Pitch surface
   
• Pressure angle (ø)
   
• Root diameter
   
• Tooth Profile
   
• Whole depth
   
• Working depth
   
• Worm gears:
  • Lead
  • Linear pitch (p)
  • Lead angle (λ)
  • Pitch diameter (D_w)