# rotationStiffness The per-axis rotational stiffness of the joint. ``` var rotationStiffness: SIMD3 ``` ## Discussion A joint with higher stiffness rotates less to reach demands. Values are in the closed range `[0, 1]`, where `0` means free to rotate, and `1` is no movement. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)