Ball Screw vs Lead Screw, What’s the Difference Between Them


Ball screws and lead screws are both mechanical components with different properties and purposes. This post will go over their definitions, applications, and the difference between a ball screw and a lead screw.

What Is a Ball Screw?

A ball screw is a mechanical linear actuator used in linear motion systems such as CNC machines, robotic arms, and high-precision industrial equipment. It is used to convert rotary motion into linear motion with minimal friction and high accuracy. The ball screw consists of a threaded shaft (screw) and a nut with a series of ball bearings. The ball bearings roll along the groove in the screw shaft as it rotates, transferring the rotational motion into linear motion. This design allows the ball screw to move with high precision and low friction, with no sliding movement between the screw and nut.


Ball screws are preferred over other types of linear motion systems because they have a very low coefficient of friction and can be manufactured to high precision. This results in less wear and tear, longer operational life, and better accuracy in positioning and positioning control. Ball screws are used in various applications such as precision machine tools, aerospace and military equipment, medical devices, semiconductor fabrication, and robotics. They come in various sizes, load capacities, and accuracy classes to suit different requirements. The choice of a ball screw depends on several factors, including the required travel distance, load capacity, speed, precision, and positioning accuracy. Additionally, factors such as temperature, vibration, and contamination also need to be considered when choosing a ball screw for a specific application.

What Is a Lead Screw?

A lead screw, also known as a power screw or translation screw is a mechanical power transmission used for linear motion in a wide variety of applications, such as machine tools, elevators, linear actuators, and 3D printers. Lead screws convert rotary motion into linear motion by using a threaded shaft or screw and a mating nut. The lead screw consists of a threaded shaft with a helical groove and a corresponding nut that fits onto the shaft. When the shaft is rotated, the nut moves linearly along the shaft, making it a useful component for linear motion control systems.


The lead screw’s threads can be designed with various pitches, which determines the travel distance of the nut per revolution of the screw. The lead screw’s thread pitch determines its mechanical advantage, speed, and accuracy. Lower-pitch leads screws move relatively slower but provide higher precision, while higher-pitch lead screws move faster but provide lower accuracy. Lead screws are often used in applications where accurate straight-line motion is needed, and where high-force, low-speed conditions are required. Since lead screws have physical contact between their screw threads and the nut, they can produce friction, which reduces mechanical efficiency and can lead to wear over time. If the lead screw is not adequately lubricated or designed, it can experience higher torque, be noisy, and produce a vibration that can affect the system’s overall performance.

Ball Screw vs Lead Screw, What's the Difference?

Lead screws are often compared to ball screws, but ball screws are usually more expensive. Ball screws use ball bearings inside the nut to provide smooth, efficient movement, but their higher accuracy and precision come at a higher cost.

– Design: Ball screws have a screw with a highly polished groove that contains a series of ball bearings. The ball bearings allow the nut to move with low friction and high accuracy along the screw’s length. The nut also has ball bearings that match the screw’s grooves, resulting in even lower friction, less vibration, and smoother operation. In contrast, lead screws have a simple screw thread and a nut, with the nut sliding directly on the screw’s surface. The thread pitch is variable and can be changed to modify the speed and torque.

– Performance: Ball screws provide higher accuracy, better efficiency, and faster travel speeds than lead screws. Ball screws offer better performance because of their lower friction and the ability to distribute loads evenly. They can carry higher loads at higher speeds than lead screws, making them ideal for applications requiring high-precision linear motion, such as CNC machines and robotics. Lead screws are less expensive than ball screws and can provide sufficient performance in low to medium-accuracy linear motion applications.

– Cost: Ball screws are more expensive than lead screws because of their intricate design, ball bearings, and manufacturing procedures. Lead screws are simple and less expensive to produce than ball screws.

– Accuracy: Ball screws offer more precision and accuracy than lead screws because they have a reduced backlash, and ball bearings distribute loads evenly, allowing for smoother movement. Ball screws are capable of much tighter tolerances for linear positioning. In contrast, lead screws have more backlash and require more lubrication to reduce the friction between the nut and screw.

– Maintenance: Ball screws require periodic lubrication or greasing to maintain their smooth movement and ensure performance. Since ball screws use ball bearings, they require more maintenance and care to prevent contamination and wear. In contrast, lead screws require fewer maintenance and lubrication needs because they lack ball bearings and have fewer moving parts.


Ball screws offer high-speed, efficient, accurate, and smooth operation but, are expensive, have higher maintenance costs and are more complex. In contrast, lead screws offer a simpler design, low cost, and lower maintenance needs but lack the precision and speed capabilities of ball screws. The choice between ball screws and lead screws depends on the specific application requirements, budget, and performance needs.