Ball Screws vs Lead Screws: What’s Best for Motion Control Applications?

Ball screws and lead screws are both used in a variety of motion control applications. Motion control relates to automation and is all about moving individual parts of a machine in a controlled and repeatable manner using a controller, a motor, and an actuator. Motion control is used in various automation applications, including micromanufacturing, precision engineering, industrial manufacturing, and testing environments. 

Learn all about both ball screws and lead screws, including how they differ and which one is appropriate for what type of job in your motion control applications.

What is a ball screw?

Ball screws are a threaded shaft that provides a helical path for ball bearings, which behave like a screw while providing minimal friction. Generally, they are built to much higher tolerances than standard acme or lead screws and are well-suited to high-precision applications. The ball assembly acts as the nut, while the threaded shaft is the screw. Ball screws tend to be rather bulky due to the need to have a mechanism to recirculate the balls. Because ball screws are not self-locking, a braking system would need to be included in the overall design.

The advantages of ball screws

• Less torque is required than for lead screws due to their efficiency; therefore, smaller motors can be used
• Greater positional accuracy than lead screws
• Low friction means that they provide a smoother motion and can run at cooler temperatures
• Longer lifespan, needing replacement less frequently
• High-speed movement achievable for continuous periods
• It can be adjusted for preload.

What is a lead screw?

A lead screw consists of the same threaded screw and nut configuration of linear motion device as the ball screw. However, it has no bearings or rollers, and the screw threads are in direct contact with the moving nut component. Higher forces are possible with lead screws, but the direct contact creates more friction, therefore requiring more power from the motor.

Advantages of lead screws

• They do not require a braking system as they are self-locking
• Suited to vertical applications
• Quieter than ball screws
• Flexible configuration
• Can carry heavier loads than ball screws
• They are less expensive than ball screws.

Ball Screws vs Lead Screws: Which Is Right for Your Application?

Both ball screws and lead screws are designed based on similar principles and to carry out the same job in terms of motion control. However, they are suited to different types of applications. A ball screw is most suited to applications that require speed, accuracy, and precision, as well as high levels of usage. Lead screws are suited to applications where speed is not critical, and they will not see high levels of use but where significant linear motion is required on a budget.

Knowing the advantages of both screws, you should have an idea of which screw is best for your application. If you are looking for UK ball screw suppliers, Matara manufactures and supplies both linear ball supports and ground ball screws, as well as all the linear rail clamps and linear guides you need. Matara are experts in precision machining and will machine both ends of a ball screw, then turn, thread, and mill it within two hours for rapid delivery. If you would like more information from the experts in ball screws and lead screws, be sure to contact us or check out our technical articles and case studies for all you need to know.