Precision (Lead Error, Friction Torque, Critical Tolerances)
If you see blue and grey squares under a photo or drawing, ...
...then click on them to display further content.
Under the headline "precision" DIN / ISO standards are explained as they apply to ball screws, how accuracies are defined, and the acceptance or specification criteria derived from these standards.
Furthermore here you will find our recommendation for Mounting Tolerances.
The DIN standard differentiates between positioning ball screws and transport ball screws.
Positioning ball screws are normally used in high-precision applications (like machine tool) and are usually equipped with a ground ball thread.
Transport ball screws are predominantly used for travelling and moving applications. Typical applications are axes for handling systems. Ball thread of such screws is usually rolled or whirled. Per DIN standard the tolerance classes for Positioning ball screws are described as "P" while transport ball screws classes are described as "T".
Steinmeyer uses this designation as per DIN:
P0 - P5 for Positioning ball screws
T5 - T10 for Transport ball screws
In general, all acceptance criteria should be reviewed and agreed upon between Steinmeyer and our customer. This is especially relevant for those applications where special demands are required, for example a lead accuracy of class 5 but friction torque variation consistent with accuracy class 1. In this example, Steinmeyer produces a ball screw with economical class 5 lead accuracy but with much lower friction torque variation.
If such custom specifications are not established, standard values of the respective accuracy class apply.
The following pages offer extensive useful information for the application engineer. We tried to present this in a clear and simple manner. Use the links provided to view detailed information relating to specific subjects. We included "back" links to take you to the previous page.
Make use of the links - not all pages appear in the menu!