Torsion Spring Terminology

Active Coils: The number of coils in the spring that are compressed or extended when it is under load.

Angular Deflection: The angle of rotation as measured from the free position to the installed, intermediate or final positions.

Free Angle: The angle between the arms of a torsion spring when the spring is in the unloaded position.

Inner diameter: The inner diameter of the spring, which is the diameter of the circle that the wire makes when the spring is not under any load.

Leg Length: The length of the straight sections at each end of the spring, which are used to attach the spring to other components.

Mandrel: A rod or shaft over which a torsion spring operates.

Material Type: The type of material used to make the spring, which can affect its strength, durability, and other properties.

Maximum Deflection: The maximum amount that the spring can be twisted before it reaches its elastic limit and starts to deform permanently.

Outer Diameter: The outer diameter of the spring, which is the diameter of the circle that the wire makes when it is wound into a spiral.

Radius: The bend radius at which a load is applied to a leg. The radius is usually assumed to be equal to ½ the leg length.

Torque: A twisting action in torsion springs which produces rotation, equal to the load multiplied by the distance from the load to the axis of the spring body.

Spring Rate: The amount of torque that the spring exerts for a given angle of twist, which is usually measured in units of torque per unit of angle (such as Nm/degree or lb-in/radian).

Total Coils: The number of coils in the spring when it is under no load.

Wire Diameter: The diameter of the wire used to make the spring, which is typically specified in inches or millimeters.

SNMHardware provides many types of torsion springs and also undertakes the manufacturing of customized torsion springs.