Screw Lead

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How far a screw's nut travels along the axis for one full turn of the screw.

Lead is the distance a nut travels along the axis of a screw (a threaded transmission part that converts rotation into linear motion) for one complete turn, equal to the thread pitch multiplied by the number of thread starts. It functions like a “gear ratio” between rotation and linear motion: a smaller lead means the same motor torque produces more force and finer position resolution, but slower linear speed; a larger lead does the opposite. When designing a humanoid's linear actuator, or the micro lead screw driving a dexterous hand, the lead has to be chosen together with motor speed, torque, and the force required. A trapezoidal screw with a small lead can also be self-locking, meaning the load can't push it back once power is cut.

ExampleWith a ball screw with a 5 mm lead, at a motor speed of 3,000 rpm, the nut moves at 3,000 ÷ 60 × 5 = 250 mm/s.

Also called: Lead (Screw)
Related: Ball Screw · Planetary Roller Screw · Linear Actuator (Electric Cylinder) · Micro Lead Screw · Trapezoidal Lead Screw & Self-Locking · Gear Ratio
Sources: Leadscrew - Wikipedia
Screw thread (Lead, pitch, and starts) - Wikipedia