CNBTR 5PCS Brass Worm Gear | Gear Module: 0.5 | 4mm Bore Diameter | 9.8mm OD | Worm Length 20mm | Thread Length 12mm

["【Brass Gears】Brass gears have low friction and dissipate heat better than cast iron gears to provide a long service life for both the gear and the worm. They’re also more corrosion resistant than cast iron gears","【Pitch Module 0.5】 This worm gear pack comes with a wheel and a worm of the same pitch module 0.5. Gears with a module of 0.5 have small, closely spaced teeth that run smoothly and quietly at high speeds","【4MM Bore】The worm gears have a 4mm diameter bore to insert a shaft of 4mm diameter","【9.8MM OD/20mm Length】 These worms have a 9.8mm outside diameter and overall length 20mm, and 12mm thread length to work with worm wheels","【Applications】Worms are used with worm wheels to reduce speeds or increase torque in mechanical applications that operate in confined spaces, such as power steering, machine tools, elevators, and chain blocks"]