--- name: TorsionSpringConstraint last_updated: 2026-06-10T23:09:12Z inherits: - Constraint - Instance - Object type: class memory_category: BaseParts summary: "A rotational spring that opposes the angular motion between two axes." --- # Class: TorsionSpringConstraint > A rotational spring that opposes the angular motion between two axes. ## Description A **TorsionSpringConstraint** applies a torque based on a relative angle and a relative angular velocity. Specifically, torsion springs try to bring two axes from two parts together in a compliant way. Correct orientation of a torsion spring's attachments is important. The constraint will attempt to bring the [SecondaryAxis](/docs/reference/engine/classes/Attachment.md) of each attachment into alignment. When building mechanisms like swinging doors, ensure that the secondary axes are **perpendicular** to the intended axis of rotation. When configuring this constraint, it may be helpful to study [Roblox Units](/docs/en-us/physics/units.md) to understand how Roblox units compare to metric units. #### Damping The [Damping](/docs/reference/engine/classes/TorsionSpringConstraint.md) value controls how fast the spring's oscillation dies down. A value of 0 allows the spring to oscillate endlessly, while higher values bring the spring to a rest more quickly. #### Stiffness [Stiffness](/docs/reference/engine/classes/TorsionSpringConstraint.md) sets the torsional strength of the spring. Higher values create a spring that responds with more force. #### Limits Enabling the [LimitsEnabled](/docs/reference/engine/classes/TorsionSpringConstraint.md) property exposes the [MaxAngle](/docs/reference/engine/classes/TorsionSpringConstraint.md) value to restrict the spring's range within a cone; it also exposes the [Restitution](/docs/reference/engine/classes/TorsionSpringConstraint.md) value which defines the elasticity of the attachments when they reach their limit. ## Properties ### Property: TorsionSpringConstraint.Coils ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Appearance", "capabilities": [ "Physics" ], "simulationAccess": true } ``` This property indicates the number of spring coils for visualization. Default value is 8. ### Property: TorsionSpringConstraint.CurrentAngle ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": false, "can_save": true }, "thread_safety": "ReadSafe", "category": "Derived", "capabilities": [ "Physics" ], "simulationAccess": true } ``` The current angle, in degrees, of the torsion spring's limiting cone. The limiting cone is formed at the position of the constraint's [Attachment0](/docs/reference/engine/classes/Constraint.md) around its secondary axis with an angle equal to [MaxAngle](/docs/reference/engine/classes/TorsionSpringConstraint.md). ### Property: TorsionSpringConstraint.Damping ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Spring", "capabilities": [ "Physics" ], "simulationAccess": true } ``` Damping constant for the [TorsionSpringConstraint](/docs/reference/engine/classes/TorsionSpringConstraint.md). Multiplied to the velocity of the constraint's [Attachments](/docs/reference/engine/classes/Attachment.md) to reduce the spring force applied. ### Property: TorsionSpringConstraint.LimitsEnabled ```json { "type": "boolean", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Spring", "capabilities": [ "Physics" ], "simulationAccess": true } ``` This property, when enabled, limits the relative angular motion of the secondary axes of attachments through a cone constraint. The default value is false. ### Property: TorsionSpringConstraint.MaxAngle ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Limits", "capabilities": [ "Physics" ], "simulationAccess": true } ``` This property determines the maximum angle (in degrees) of the torsion spring's limiting cone. The limiting cone is formed at the position of the constraint's [Attachment0](/docs/reference/engine/classes/Constraint.md) around its secondary axis with an angle equal to [MaxAngle](/docs/reference/engine/classes/TorsionSpringConstraint.md). Default value is 45 degrees. ### Property: TorsionSpringConstraint.MaxTorque ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Spring", "capabilities": [ "Physics" ], "simulationAccess": true } ``` This property determines the maximum torque supported by the torsion spring. Defaults to 1000. ### Property: TorsionSpringConstraint.Radius ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Appearance", "capabilities": [ "Physics" ], "simulationAccess": true } ``` This property indicates the visualization radius of the spring, in studs. Default value is 0.4. ### Property: TorsionSpringConstraint.Restitution ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Limits", "capabilities": [ "Physics" ], "simulationAccess": true } ``` This property defines how elastic [Attachments](/docs/reference/engine/classes/Attachment.md) connected by a [TorsionSpringConstraint](/docs/reference/engine/classes/TorsionSpringConstraint.md) are when they reach the end of the range specified by [MaxAngle](/docs/reference/engine/classes/TorsionSpringConstraint.md), when [LimitEnabled](/docs/reference/engine/classes/TorsionSpringConstraint.md) is true. The value defaults to 0 and can be any floating number within the range of 0 and 1. ### Property: TorsionSpringConstraint.Stiffness ```json { "type": "float", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "thread_safety": "ReadSafe", "category": "Spring", "capabilities": [ "Physics" ], "simulationAccess": true } ``` In the absence of damping, this property is proportional to the opposing torque of the spring. For instance, higher stiffness results in a larger opposing torque, and smaller stiffness results in a smaller opposing torque. The larger the torque value, the faster the axes are pushed together when the relative angle is positive (or away from each other if the relative angle is negative). The value defaults to 100. ### Property: TorsionSpringConstraint.LimitEnabled *(hidden)* ```json { "type": "boolean", "access": "ReadWrite", "security": { "read": "None", "write": "None" }, "serialization": { "can_load": true, "can_save": true }, "deprecated": true, "thread_safety": "ReadSafe", "category": "Spring", "capabilities": [ "Physics" ], "simulationAccess": true } ``` > **Deprecated:** This property is deprecated. Use [LimitsEnabled](/docs/reference/engine/classes/TorsionSpringConstraint.md) instead. ## Inherited Members ### From [Constraint](/docs/reference/engine/classes/Constraint.md) - **Property `Active`** (`boolean`): Indicates if the constraint is currently active in the world. - **Property `Attachment0`** (`Attachment`): The Attachment that is connected to - **Property `Attachment1`** (`Attachment`): The Attachment that is connected to - **Property `Color`** (`BrickColor`): The color of the constraint. - **Property `Enabled`** (`boolean`): Toggles whether or not the constraint is enabled. - **Property `Visible`** (`boolean`): Toggles the constraint's visibility. - **Method `GetDebugAppliedForce(bodyId: int): Vector3`**: *(deprecated)* - **Method `GetDebugAppliedTorque(bodyId: int): Vector3`**: *(deprecated)* ### From [Instance](/docs/reference/engine/classes/Instance.md) - **Property `Archivable`** (`boolean`): Determines if an Instance and its descendants can be cloned using - **Property `archivable`** (`boolean`): *(deprecated, hidden)* - **Property `Capabilities`** (`SecurityCapabilities`): The set of capabilities allowed to be used for scripts inside this - **Property `Name`** (`string`): A non-unique identifier of the Instance. - **Property `Parent`** (`Instance`): Determines the hierarchical parent of the Instance. - **Property `PredictionMode`** (`PredictionMode`): - **Property `RobloxLocked`** (`boolean`): A deprecated property that used to protect CoreGui objects. *(hidden)* - **Property `Sandboxed`** (`boolean`): When enabled, the instance can only access abilities in its `Capabilities` - **Property `UniqueId`** (`UniqueId`): A unique identifier for the instance. - **Method `AddTag(tag: string): ()`**: Applies a tag to the instance. - **Method `children(): Instances`**: Returns an array of the object's children. *(deprecated)* - **Method `ClearAllChildren(): ()`**: This method destroys all of an instance's children. - **Method `Clone(): Instance`**: Create a copy of an instance and all its descendants, ignoring instances - **Method `clone(): Instance`**: *(deprecated)* - **Method `Destroy(): ()`**: Sets the Instance.Parent property to `nil`, locks the - **Method `destroy(): ()`**: *(deprecated)* - **Method `FindFirstAncestor(name: string): Instance?`**: Returns the first ancestor of the Instance whose - **Method `FindFirstAncestorOfClass(className: string): Instance?`**: Returns the first ancestor of the Instance whose - **Method `FindFirstAncestorWhichIsA(className: string): Instance?`**: Returns the first ancestor of the Instance for whom - **Method `FindFirstChild(name: string, recursive?: boolean): Instance?`**: Returns the first child of the Instance found with the given name. - **Method `findFirstChild(name: string, recursive?: boolean): Instance`**: *(deprecated)* - **Method `FindFirstChildOfClass(className: string): Instance?`**: Returns the first child of the Instance whose - **Method `FindFirstChildWhichIsA(className: string, recursive?: boolean): Instance?`**: Returns the first child of the Instance for whom - **Method `FindFirstDescendant(name: string): Instance?`**: Returns the first descendant found with the given Instance.Name. - **Method `GetActor(): Actor?`**: Returns the Actor associated with the Instance, if any. - **Method `GetAttribute(attribute: string): Variant`**: Returns the value which has been assigned to the given attribute name. - **Method `GetAttributeChangedSignal(attribute: string): RBXScriptSignal`**: Returns an event that fires when the given attribute changes. - **Method `GetAttributes(): Dictionary`**: Returns a dictionary of the instance's attributes. - **Method `GetChildren(): Instances`**: Returns an array containing all of the instance's children. - **Method `getChildren(): Instances`**: *(deprecated)* - **Method `GetDebugId(scopeLength?: int): string`**: Returns a coded string of the debug ID used internally by Roblox. - **Method `GetDescendants(): Instances`**: Returns an array containing all of the descendants of the instance. - **Method `GetFullName(): string`**: Returns a string describing the instance's ancestry. - **Method `GetStyled(name: string, selector: string?): Variant`**: Returns the styled or explicitly modified value of the specified property, - **Method `GetStyledPropertyChangedSignal(property: string): RBXScriptSignal`**: - **Method `GetTags(): Array`**: Gets an array of all tags applied to the instance. - **Method `HasTag(tag: string): boolean`**: Check whether the instance has a given tag. - **Method `IsAncestorOf(descendant: Instance): boolean`**: Returns true if an Instance is an ancestor of the given - **Method `IsDescendantOf(ancestor: Instance): boolean`**: Returns `true` if an Instance is a descendant of the given - **Method `isDescendantOf(ancestor: Instance): boolean`**: *(deprecated)* - **Method `IsPropertyModified(property: string): boolean`**: Returns `true` if the value stored in the specified property is not equal - **Method `QueryDescendants(selector: string): Instances`**: - **Method `Remove(): ()`**: Sets the object's `Parent` to `nil`, and does the same for all its *(deprecated)* - **Method `remove(): ()`**: *(deprecated)* - **Method `RemoveTag(tag: string): ()`**: Removes a tag from the instance. - **Method `ResetPropertyToDefault(property: string): ()`**: Resets a property to its default value. - **Method `SetAttribute(attribute: string, value: Variant): ()`**: Sets the attribute with the given name to the given value. - **Method `WaitForChild(childName: string, timeOut: double): Instance`**: Returns the child of the Instance with the given name. If the - **Event `AncestryChanged`**: Fires when the Instance.Parent property of this object or one of - **Event `AttributeChanged`**: Fires whenever an attribute is changed on the Instance. - **Event `ChildAdded`**: Fires after an object is parented to this Instance. - **Event `childAdded`**: *(deprecated)* - **Event `ChildRemoved`**: Fires after a child is removed from this Instance. - **Event `DescendantAdded`**: Fires after a descendant is added to the Instance. - **Event `DescendantRemoving`**: Fires immediately before a descendant of the Instance is removed. - **Event `Destroying`**: Fires immediately before (or is deferred until after) the instance is - **Event `StyledPropertiesChanged`**: Fires whenever any style property is changed on the instance, including ### From [Object](/docs/reference/engine/classes/Object.md) - **Property `ClassName`** (`string`): A read-only string representing the class this Object belongs to. - **Property `className`** (`string`): *(deprecated)* - **Method `GetPropertyChangedSignal(property: string): RBXScriptSignal`**: Get an event that fires when a given property of the object changes. - **Method `IsA(className: string): boolean`**: Returns true if an object's class matches or inherits from a given class. - **Method `isA(className: string): boolean`**: *(deprecated)* - **Event `Changed`**: Fires immediately after a property of the object changes, with some