Description
Worms appear similar to a coarse screw thread but run with a worm gear.

Manufacturing processes
Worms are formed by milling the teeth on a special machine. They will then usually be carburized and thread ground on another dedicated machine.

Worm gears are usually bronze or cast iron and hobbed to size. Worm gears are tested for backlash and patterned with either a mating worm or a master.

Capacities
Brad Foote Gear Works can make ground tooth worm shafts to 12” outside diameter, 100” overall length and 15” face length. Worm gears can be hobbed to 140” outside diameter.