What To Look for When Choosing a Ball Screw

What To Look for When Choosing a Ball Screw

The best ball screws are manufactured with the highest quality materials and customized to suit the job they’re designated for. Choosing a ball screw wisely results in precise and accurate results and an application or machine that lasts a long time. In this article, we’ll discuss what to look for when choosing a ball screw to help you narrow down the process.

The Right Manufacturer

Nothing is more important than starting with the right manufacturer when considering what to look for when choosing a ball screw.

An excellent manufacturer chooses the highest quality steel, understands the importance of temperature control during the manufacturing process, and can tell you which ball screw you need for the required job. Look for a manufacturer with plenty of experience and knowledge of the industry.

Speed Matters

There are two types of speeds that matter when using a ball screw: critical speed and characteristic speed. Let’s look at the differences.

Critical Speed

The critical speed of a ball screw is the speed shaft’s natural frequency. The natural frequency is the light bending or sagging of the screw shaft that naturally happens when in operation because of its weight.

Besides the natural frequency, there is vibration or whipping like a jump rope when a screw is rotating. This is the rotational frequency. When resonance occurs, meaning both the natural frequency and the rotational frequency match, damage to the ball screw is likely, as is complete screw assembly failure.

It’s critical that the screw shaft has a proper end support method to assure the correct critical speed and prevent damage to the screw assembly.

Characteristic Speed

The ball nut determines the characteristic speed of the ball screw assembly, specifically the force on the balls during recirculation. The mass and speed of the balls as they travel through the nut determine this force. Typically, internal paths of recirculation produce higher characteristic speeds, while external paths produce lower ones.

Critical and characteristic speeds in the ball screw assembly are essential in providing ball screws that have a long life and operate efficiently.


Accuracy is how close an assembly comes to its command position, and it’s essential in a ball screw assembly. The maximum error between what was expected and the actual position determines accuracy.

Ball screw accuracy is commonly measured with lead accuracy. Lead accuracy tells how far the ball nut traveled within a complete turn of the screw.

Life of the Ball Screw

When a ball screw shows signs of flaking on the balls and ball grooves, it’s reaching its maximum life cycle. Each ball screw is designed to reach a total number of rotations before this should start happening.

Ball screws can be repaired or rebuilt when this happens. Still, you want to choose a ball screw according to its determined life cycle and ability. Also, follow the manufacturer’s instructions to properly maintain and care for the ball screw assembly.

We hope our advice on what to look for when choosing a ball screw helps you in choosing the best screw assembly for your application.

Wedin International is your trusted source for Acme screw products and ball screw manufacturing. You can count on the Wedin name for all your motion and linear control systems. Contact us with any questions about repairs, rebuilding, or purchasing.