Stretching spring is a type of spiral spring used to resist tension. The tension spring is stretched and works under tension. In mechanisms that require tension to restore components to their original position, tension springs are essential. Stretching springs or spiral stretching springs can store energy and apply tension. They are usually made of circular threads and tightly wound with initial tension. Applications include tape players, garage doors, scales, and automatic washing machines.

main features 
Shape and design: The tension spring is tightly wound, usually with hooks, loops, or end coils at both ends. These ends are connected to different components, providing a mechanism for applying force when the spring is pulled apart.
Material: These springs are typically made of high tensile materials such as stainless steel, piano wire, or other durable alloys. This ensures that they can withstand repeated stretching and return to their original shape without significant wear or deformation.
Load and deflection: The characteristics of a tension spring are its load (the force required to stretch the spring) and deflection (the distance the spring can stretch). The design of a spring determines its load capacity and deflection range.

The advantages of using tension springs
Energy storage: Stretching springs can effectively store mechanical energy when stretched, and can return to their original position after release. This makes them an ideal choice for applications that require tension and rebound force.
Durability: Stretch springs are made of sturdy materials with the ability to resist fatigue, wear, and environmental factors, ensuring a long service life even after repeated use.
Multifunctionality: Stretch springs come in various sizes, materials, and end configurations, and can be customized to accommodate a wide range of applications from small precision equipment to large industrial machinery.

The tension spring is subjected to torsional stress inside the body. Its design is similar to a compression spring, but there are a few differences:
Most tension springs are wound with initial tension.
They do not have sturdy stopping devices to prevent overload, so the stress level is usually lower than that of compression springs.

We offer tension springs with the following properties:
End: The end types of tension springs provided by SMSC include full ring and mechanism ring configurations. Before forming a loop or hook, the loop or hook may have a transverse center transition from the previous coil.
Tolerance: The tolerance of a tension spring depends on its wire diameter and body diameter. The actual value of tolerance depends on the specifications of these tension coil springs. Usually, the tolerance range for these springs is between+/-10% and+/-5%.

The types of tension springs we offer:
Double twisted ring: used for secure and stable anchoring, and has enhanced durability.
Extended Eye Ring: Perfect for applications that require extra length and flexibility.
Rectangular hooks: designed to achieve powerful performance and multifunctional connection points.
Bias hook: suitable for applications where accessories exceed the diameter of the coil.
V-shaped hook: Very suitable for professional applications that require unique hook configurations.

Stretching springs are known for their ability to store mechanical energy in coils and release it when expanding. These springs are designed to handle tension, absorb and store tension to resist forces applied at their ends. Usually, both ends of the tension spring are connected to the component and tension is applied through hooks or loops. When force is applied and the components separate, the spring will attempt to return to its original position. The initial tension inside the spring determines the tightness of the coil, which is crucial for evaluating the load capacity of a specific application. Although springs follow Hooke's law when not stretched or compressed, they follow simple harmonic motion when a load is applied. The end of the tension spring bears greater tension due to the energy stored in the ring or hook, while the coil has no stress when tightly wound. The energy distribution between the hook and the coil will affect the performance of the spring.

The initial tension applied determines the distance between these coils, and by controlling the initial tension, springs can be customized to meet specific load requirements. The coiled design of the spring provides strength and elasticity. The tension spring is tightly wound and maintains a coiled state in a stationary state. We include interfaces such as eyes, hooks, or loops on both ends for easy connection to other components.