Most suitable choice of gearing when high drive decrease is required. Worm Wheels Worm wheel gear resemble spur gears with the addition of a throat cut in to the O.D. of wheel. The throat permits the worm wheel to totally envelope the threads of the worm. Threads, not teeth are cut on the worm, and by adjusting the amount of threads, different ratios can be achieved without altering mounting arrangements. A distinctive feature of Worm and 
Wheel assemblies is definitely their capability to prohibit back driving
Pitch: 16 to 64 DP and 1.5 to .5 MOD
Materials: Brass for Worm Gear and Stainless Steel for Worm
Single, Dual or Quad Start