Boston Gear 30217398 HDSH-1 single-thread hardened steel open worm gear for use with matching worm wheels in general industrial power transmission applications. Part of Boston Gear's open gearing line, suitable for right-angle drives requiring smooth, quiet operation and high reduction ratios.

When used with worm gears, Boston Gear worms provide an effective answer for power transmission applications requiring high ratio speed reduction in a limited space using right angle (90°), non-intersecting shafts. Manufactured from acetal, nylon, and hardened and unhardened steel, they offer the smoothest, quietest form of gearing when properly applied. Because the efficiency of a worm gear drive depends on the lead angle and number of starts on the worm, it important to keep the ratio as low as possible. It is equally important that worms and worm gears used together must have the same diametrical pitch and threads.