Trapezoidal vs. Ball Screw: Which One to Use in an Actuator?
In an electric linear actuator, the part that converts the motor’s rotation into linear motion is the spindle. The spindle type directly affects the actuator’s efficiency, speed, noise level, lifetime and whether it holds the load when power is cut. The two most common types are the trapezoidal spindle and the ball screw.
Trapezoidal spindle
The nut slides along the spindle. Because friction is relatively high, efficiency is lower; however, thanks to this friction the actuator holds the load by itself in most applications when the motor stops (self-locking). It runs quietly, has a simple design and is low cost.
- Intermittent applications: hospital beds, chairs, desks, furniture
- Systems where the load must stay in place when power is cut
- Designs where low noise and cost are priorities
Ball screw
Recirculating balls run between the nut and the spindle, so friction is rolling rather than sliding. Efficiency is much higher, it generates less heat and is suited to higher speeds and longer operating times. On the other hand, because friction is low it usually does not self-lock; applications that must hold the load need an additional brake.
- Industrial applications with frequent and long operation
- Systems requiring high speed and precise positioning
- Battery-powered equipment where energy efficiency matters
Comparison
| Feature | Trapezoidal spindle | Ball screw |
|---|---|---|
| Working principle | Sliding friction | Rolling (balls) |
| Efficiency | Lower | High |
| Self-locking | Mostly yes | Usually no, brake required |
| Noise | Quiet | May be slightly louder |
| Duty cycle / lifetime | Intermittent use | Heavy use, long life |
| Cost | More economical | Higher |
Which one should you choose?
For applications that run a few times a day for short periods, such as medical beds, treatment chairs or height-adjustable desks, trapezoidal spindle actuators are usually the best-balanced solution. For automation applications running continuously or at high speed, ball screw solutions stand out. Duty cycle, load and noise expectations should be evaluated together; see our actuator selection guide for details.
Let us choose the right product for your application together. Send us your load, stroke, speed and operating environment details via our contact page, or use the Request a Quote button on the relevant product page; our technical team will recommend the most suitable solution.