Choosing A Trapezoidal Lead Screw

General choice criteria

When deciding which of Trapezoidal Leadscrew is best suited for the customer’s proposed application, a number of considerations should be made:

Working environment

For work environments where corrosion and oxidization are not a concern, C45 Carbon Steel screws can be used. In applications where environmental exposure is a concern, we recommend the use of A2 and A4 Stainless Steel, which are suitable in the following cases:

- In environments of 70/80% humidity and above.
- When immersed in water.
- Where oxidisation is a concern.
- Where screws cannot be easily maintained, and must be self-lubricating.
- Where components will be exposed to high working temperatures.
- In the presence of corrosive agents such as chlorides. If the application involves exposure to highly corrosive agents, please contact our Technical Department.

Positioning Accuracy

When manufacturing precision actuation components, it is vital to ensure the accuracy of our products. We provide leadscrews with accuracies of between within 3.3 µm/mm and 6.6 µm/mm, both in C45 Carbon Steel and A2 Stainless Steel.

Irreversibility

Irreversibility defines how much a nut can “backdrive” down the leadscrew. A trapezoidal screw with a helix angle of less than 2° 30' is completely irreversible, whereas a screw with an angle of over 6° is very susceptible to backdrive.

Irreversibility is especially important attribute to consider in applications where a leadscrew is mounted vertically. Significant backdrive when a mechanism is acting against gravity can potentially result in mechanical complications, and should be avoided.