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Source: Roblox Creator Hub · CC BY 4.0 · View source · Code samples: MIT Imported 2026-10-03. Formatting adapted for this site.

SpringConstraint

Inherits from: Constraint → Instance → Object

A SpringConstraint applies a force to its Attachments based on spring and damper behavior. This constraint, along with a CylindricalConstraint, is ideal for building vehicle suspension.

Note that if this constraint attaches one part (A) to another part (B) that is anchored or connected to an anchored part (Z), part A will not be locally simulated when interacting with a player.

When configuring this constraint, it may be helpful to study Roblox Units to understand how Roblox units compare to metric units.

Free Length

FreeLength defines the natural resting length of the spring. If the attachments are further apart than the free length, they are forced together; if the attachments are closer together than the free length, they are forced apart.

Damping

The Damping 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 sets the strength of the spring. Higher values create a spring that responds with more force when its attachments are closer together or further apart than FreeLength.

Limits

Enabling the LimitsEnabled property exposes the MinLength and MaxLength values for setting the minimum and maximum length of the spring. If the spring's attachments reach these limits, they stop moving apart from one another without restitution.

Inherits from: Constraint

Memory category: BaseParts

Properties

Name	Type / Returns	Description
SpringConstraint.Coils	float	The number of coils visualized on the `SpringConstraint`.
SpringConstraint.CurrentLength	float	The current distance between the constraint's `Attachments`.
SpringConstraint.Damping	float	Damping constant for the `SpringConstraint`. Multiplied to the velocity of the constraint's `Attachments` to reduce the spring force applied.
SpringConstraint.FreeLength	float	Natural resting length of the spring.
SpringConstraint.LimitsEnabled	boolean	Sets whether the `SpringConstraint` enforces a minimum and maximum length.
SpringConstraint.MaxForce	float	The maximum force the `SpringConstraint` can apply on its `Attachments`.
SpringConstraint.MaxLength	float	The maximum separation the SpringConstraint will allow if `LimitsEnabled` is true.
SpringConstraint.MinLength	float	The minimum separation the SpringConstraint will allow if `LimitsEnabled` is true.
SpringConstraint.Radius	float	The visualized radius of the spring's coils.
SpringConstraint.Stiffness	float	The strength of the spring. The higher this value the more force will be applied when the attachments are separated a different length than the `FreeLength`.
SpringConstraint.Thickness	float	The visualized thickness of the spring's coils.

Inherited from Constraint

Name	Type / Returns	Description
Constraint.Active	boolean	Indicates if the constraint is currently active in the world.
Constraint.Attachment0	Attachment	The `Attachment` that is connected to `Constraint.Attachment1`.
Constraint.Attachment1	Attachment	The `Attachment` that is connected to `Constraint.Attachment0`.
Constraint.Color	BrickColor	The color of the constraint.
Constraint.Enabled	boolean	Toggles whether or not the constraint is enabled.
Constraint.Visible	boolean	Toggles the constraint's visibility.

Inherited from Instance

Name	Type / Returns	Description
Instance.Archivable	boolean	Determines if an `Instance` and its descendants can be cloned using `Instance:Clone()`, and can be saved/published.
Instance.archivable	boolean
Instance.Capabilities	SecurityCapabilities	The set of capabilities allowed to be used for scripts inside this container.
Instance.IsInSandbox	boolean	Indicates whether the instance is inside a sandboxed container.
Instance.Name	string	A non-unique identifier of the `Instance`.
Instance.Parent	Instance	Determines the hierarchical parent of the `Instance`.
Instance.PredictionMode	PredictionMode	Reflects the client-side prediction mode applied to the instance under server-authoritative physics.
Instance.RobloxLocked	boolean	A deprecated property that used to protect `CoreGui` objects.
Instance.Sandboxed	boolean	When enabled, the instance can only access abilities in its `Capabilities` list.
Instance.UniqueId	UniqueId	A unique identifier for the instance.

Inherited from Object

Name	Type / Returns	Description
Object.ClassName	string	A read-only string representing the class this `Object` belongs to.
Object.className	string

SpringConstraint.Coils

The number of coils visualized on the SpringConstraint. This can only be set between 0 and 8.

Field	Value
type	float
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Appearance
serialization	{"can_load":true,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

SpringConstraint.CurrentLength

The current distance between the constraint's Attachments.

Field	Value
type	float
tags	["ReadOnly","NotReplicated"]
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Derived
serialization	{"can_load":false,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

SpringConstraint.Damping

Damping constant for the SpringConstraint. Multiplied to the velocity of the constraint's Attachments to reduce the spring force applied.

Field	Value
type	float
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Spring
serialization	{"can_load":true,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

SpringConstraint.FreeLength

Natural resting length of the spring.

Field	Value
type	float
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Spring
serialization	{"can_load":true,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

SpringConstraint.LimitsEnabled

Sets whether the SpringConstraint enforces a minimum and maximum length. If the constraint's Attachments reach these limits, they will simply stop moving apart from one another without restitution. If you need restitution or elasticity at the ends of the range of motion, you can combine a SpringConstraint with another constraint that allows restitution at the end of its range, such as a PrismaticConstraint or RopeConstraint.

Field	Value
type	boolean
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Spring
serialization	{"can_load":true,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

SpringConstraint.MaxForce

The maximum force the SpringConstraint can apply on its Attachments. Some spring systems can give rise to forces that grow fast leading to instability. In such cases it is recommended to set MaxForce to a reasonable value.

Field	Value
type	float
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Spring
serialization	{"can_load":true,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

SpringConstraint.MaxLength

The maximum separation the SpringConstraint will allow if LimitsEnabled is true.

Field	Value
type	float
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Limits
serialization	{"can_load":true,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

SpringConstraint.MinLength

The minimum separation the SpringConstraint will allow if LimitsEnabled is true.

Field	Value
type	float
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Limits
serialization	{"can_load":true,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

SpringConstraint.Radius

The visualized radius of the spring's coils.

Field	Value
type	float
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Appearance
serialization	{"can_load":true,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

SpringConstraint.Stiffness

The strength of the spring. The higher this value the more force will be applied when the attachments are separated a different length than the FreeLength.

Field	Value
type	float
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Spring
serialization	{"can_load":true,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

SpringConstraint.Thickness

The visualized thickness of the spring's coils.

Field	Value
type	float
security	{"read":"None","write":"None"}
thread safety	ReadSafe
category	Appearance
serialization	{"can_load":true,"can_save":true}
capabilities	["Physics"]
simulationAccess	true

Methods

Inherited from Constraint

Name	Type / Returns	Description
Constraint:GetDebugAppliedForce	Vector3
Constraint:GetDebugAppliedTorque	Vector3

Inherited from Instance

Name	Type / Returns	Description
Instance:AddTag	()	Applies a tag to the instance.
Instance:children	Instances	Returns an array of the object's children.
Instance:ClearAllChildren	()	This method destroys all of an instance's children.
Instance:Clone	Instance	Create a copy of an instance and all its descendants, ignoring instances that are not `Archivable`.
Instance:clone	Instance
Instance:Destroy	()	Sets the `Instance.Parent` property to `nil`, locks the `Instance.Parent` property, disconnects all connections, and calls `Destroy()` on all children.
Instance:destroy	()
Instance:FindFirstAncestor	Instance?	Returns the first ancestor of the `Instance` whose `Instance.Name` is equal to the given name.
Instance:FindFirstAncestorOfClass	Instance?	Returns the first ancestor of the `Instance` whose `Object.ClassName` is equal to the given className.
Instance:FindFirstAncestorWhichIsA	Instance?	Returns the first ancestor of the `Instance` for whom `Object:IsA()` returns true for the given className.
Instance:FindFirstChild	Instance?	Returns the first child of the `Instance` found with the given name.
Instance:findFirstChild	Instance
Instance:FindFirstChildOfClass	Instance?	Returns the first child of the `Instance` whose `ClassName` is equal to the given class name.
Instance:FindFirstChildWhichIsA	Instance?	Returns the first child of the `Instance` for whom `Object:IsA()` returns true for the given className.
Instance:FindFirstDescendant	Instance?	Returns the first descendant found with the given `Instance.Name`.
Instance:GetActor	Actor?	Returns the `Actor` associated with the Instance, if any.
Instance:GetAttribute	Variant	Returns the value which has been assigned to the given attribute name.
Instance:GetAttributeChangedSignal	RBXScriptSignal	Returns an event that fires when the given attribute changes.
Instance:GetAttributes	Dictionary	Returns a dictionary of the instance's attributes.
Instance:GetChildren	Instances	Returns an array containing all of the instance's children.
Instance:getChildren	Instances
Instance:GetDebugId	string	Returns a coded string of the debug ID used internally by Roblox.
Instance:GetDescendants	Instances	Returns an array containing all of the descendants of the instance.
Instance:GetFullName	string	Returns a string describing the instance's ancestry.
Instance:GetStyled	Variant	Returns the styled or explicitly modified value of the specified property, or else the default property value if it hasn't been styled/modified.
Instance:GetStyledPropertyChangedSignal	RBXScriptSignal	Returns an event that fires when the given style property changes on the instance.
Instance:GetTags	Array	Gets an array of all tags applied to the instance.
Instance:HasTag	boolean	Check whether the instance has a given tag.
Instance:IsAncestorOf	boolean	Returns true if an `Instance` is an ancestor of the given descendant.
Instance:IsDescendantOf	boolean	Returns `true` if an `Instance` is a descendant of the given ancestor.
Instance:isDescendantOf	boolean
Instance:IsPropertyModified	boolean	Returns `true` if the value stored in the specified property is not equal to the code-instantiated default.
Instance:QueryDescendants	Instances	Returns an array containing all descendants of the instance that match the `selector` string.
Instance:Remove	()	Sets the object's `Parent` to `nil`, and does the same for all its descendants.
Instance:remove	()
Instance:RemoveTag	()	Removes a tag from the instance.
Instance:ResetPropertyToDefault	()	Resets a property to its default value.
Instance:SetAttribute	()	Sets the attribute with the given name to the given value.
Instance:WaitForChild	Instance	Returns the child of the `Instance` with the given name. If the child does not exist, it will yield the current thread until it does.

Inherited from Object

Name	Type / Returns	Description
Object:GetPropertyChangedSignal	RBXScriptSignal	Get an event that fires when a given property of the object changes.
Object:IsA	boolean	Returns true if an object's class matches or inherits from a given class.
Object:isA	boolean

Events

Inherited from Instance

Name	Type / Returns	Description
Instance.AncestryChanged		Fires when the `Instance.Parent` property of this object or one of its ancestors is changed.
Instance.AttributeChanged		Fires whenever an attribute is changed on the `Instance`.
Instance.ChildAdded		Fires after an object is parented to this `Instance`.
Instance.childAdded
Instance.ChildRemoved		Fires after a child is removed from this `Instance`.
Instance.DescendantAdded		Fires after a descendant is added to the `Instance`.
Instance.DescendantRemoving		Fires immediately before a descendant of the `Instance` is removed.
Instance.Destroying		Fires immediately before (or is deferred until after) the instance is destroyed via `Instance:Destroy()`.
Instance.StyledPropertiesChanged		Fires whenever any style property is changed on the instance, including when a property is set to `nil`.

Inherited from Object

Name	Type / Returns	Description
Object.Changed		Fires immediately after a property of the object changes, with some limitations.