# Fixed joint definition reference for the LowLevelPhysics2D API

> Explore the properties you can use to configure a fixed joint in the Editor.

> **Note:**
>
> This documentation is about writing C# scripts using the `LowLevelPhysics2D` API. To use 2D physics in the Unity Editor using components like the Rigidbody 2D component, refer to [2D physics](/engine/6000.3/manual/unity2d/2d-physics.md.md) instead.

Explore the properties you can use to configure a `LowLevelPhysics2D` API fixed joint in the Unity Editor.

A fixed joint fixes two bodies to the same position and rotation with a spring.

| **Property**          | **Sub-property** | **Description**                                                                                                                                                                                                                                               |
| --------------------- | ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Local Anchor A**    | N/A              | Sets where one end of the joint connects to the first body.                                                                                                                                                                                                   |
| N/A                   | **Position**     | Sets the position where the end of the joint connects, relative to the position of the first body.                                                                                                                                                            |
| N/A                   | **Rotation**     | Sets the rotation of the anchor in degrees.                                                                                                                                                                                                                   |
| **Local Anchor B**    | N/A              | Sets where the other end of the joint connects to the second body.                                                                                                                                                                                            |
| N/A                   | **Position**     | Sets the position where the end of the joint connects, relative to the position of the second body.                                                                                                                                                           |
| N/A                   | **Rotation**     | Sets the rotation of the anchor in degrees.                                                                                                                                                                                                                   |
| **Linear Frequency**  | N/A              | Sets the stiffness of the spring that tries to keep the positions of the two bodies the same, in Hertz (cycles per second). A higher value makes the joint less stiff. The default is 0.                                                                      |
| **Linear Damping**    | N/A              | Sets how quickly the spring stops pulling or pushing. A higher value makes the joint settle more quickly. The default is 0.                                                                                                                                   |
| **Angular Frequency** | N/A              | Sets the stiffness of the spring that tries to keep the rotation of the two bodies the same, in Hertz (cycles per second). A higher value makes the joint's rotation less stiff. The default is 0.                                                            |
| **Angular Damping**   | N/A              | Sets how quickly the spring stops rotating. A higher value makes the rotation of the joint settle more quickly. The default is 0.                                                                                                                             |
| **Force Threshold**   | N/A              | Sets the amount of linear force that creates an `OnJointThreshold2D` event.                                                                                                                                                                                   |
| **Torque Threshold**  | N/A              | Sets the amount of rotational force that creates an `OnJointThreshold2D` event.                                                                                                                                                                               |
| **Tuning Frequency**  | N/A              | Sets the overall stiffness of the joint in Hertz (cycles per second). A higher value makes the joint less stiff.                                                                                                                                              |
| **Tuning Damping**    | N/A              | Sets how quickly overall the joint stops pulling or pushing. A higher value makes the joint settle more quickly.                                                                                                                                              |
| **Draw Scale**        | N/A              | Scales the joint Unity draws as a debug visualization. For more information, refer to [Draw a debug visualization of objects](/engine/6000.3/manual/unity2d/2d-physics-api/create-objects/debug-drawing.md).                                                  |
| **Collide Connected** | N/A              | Enables the shapes creating collision or trigger events when they come into contact with each other. For more information, refer to [Collisions and interactions in the LowLevelPhysics2D API](/engine/6000.3/manual/unity2d/2d-physics-api/interactions.md). |

## Additional resources

* [`PhysicsFixedJointDefinition`](/engine/6000.3/script-reference/unityengine/lowlevelphysics2d/physicsfixedjointdefinition.md)
* [Configure LowLevelPhysics2D API scenes with definitions](/engine/6000.3/manual/unity2d/2d-physics-api/properties/definitions.md)
* [Configure global LowLevelPhysics2D API settings](/engine/6000.3/manual/unity2d/2d-physics-api/properties/global-settings.md)