LEGO Technic Worm Gear (Short)

The Master of Torque and Control

The LEGO® Technic Worm Gear is a small part that delivers immense power. This specialized screw is engineered for one primary purpose: to create massive gear reduction in a very small space. When meshed with a standard spur gear, it translates the fast, low-torque rotation from a motor or hand-crank into slow, powerful, high-torque motion. Crucially, it creates a one-way, self-locking system—power can turn the worm gear to move the mechanism, but the mechanism's weight cannot turn the worm gear back. This makes it indispensable for any function that needs to hold a heavy load.

Applications for Lifting and Locking

This gear is the ultimate solution for any function that needs to be both powerful and stable.

• Cranes, Lifts, and Winches: It is the essential component for any lifting function. Once you stop turning the handle, the self-locking nature of the worm gear will hold the load securely in place without any need for a separate ratchet or brake.
• Precision Steering Systems: Use a worm gear to drive the steering rack in a vehicle. It provides slow, precise control and prevents the wheels from turning on their own, keeping the vehicle driving in a straight line.
• Linear Actuators: Build powerful and stable linear actuators for operating functions like outriggers or landing gear. The locking feature ensures they stay firmly in position once extended or retracted.

Create your most powerful functions yet by pairing this worm gear with parts from our Technic gears and axles collections.

Key Specifications

• Part ID: 27938
• Type: Worm Gear / Worm Screw
• Function: High gear reduction and self-locking motion.
• Compatibility: Meshes at a right angle with any standard Technic spur gear.

A Little Piece of Trivia

This short, single-axle-hole worm gear is a modern, more compact evolution of the original, longer worm gear (Part 4716) that was part of the Technic system for decades. This new design, introduced in 2017, allows it to be integrated into much tighter and more complex assemblies where space is limited. Its compact form factor makes it a favorite among MOC builders for creating powerful functions inside sleek, space-efficient models.

Ready to build functions that can lift anything? Add this powerful worm gear to your arsenal and lock your creations in place!

LEGO® parts are intended for builders aged 4 and up. They may pose a choking hazard for children under 3 years old.