Tension Springs

As one of the top manufacturers in the industry, we at Plymouth Spring fabricate a variety of tension (otherwise known as extension) spring designs. We offer turnable loops, turnable bolts, female thread fittings, custom tension springs as end options, and variable tension spring coil lengths.

What Are Extension Springs?

Extension springs are often engineered with initial tension allowing them to store energy and exert a 'pull' force when stretched. The energy stored within the springs creates resistance, compelling the spring to return to its original shape. Axial loading and bending cause the tensile stresses extension springs cope with.

The function of an extension spring depends on the pull forces applied by external forces, and as a result, these springs have attached points to receive these pulling forces. Often, these attachment points take the form of hook ends or loops. At Lesjöfors Stock Spring US, we keep a stringent quality check on our springs to ensure their optimum operation within your application.

Applications of Tension Springs

Tension springs are commonly used in applications such as loft hatches, garage doors, and lever-based mechanisms, these springs are integral for ensuring efficient functionality. For example, when installed in loft hatches, they provide the necessary counterbalance force to enable easy opening and closing. Similarly, in garage doors, tension springs counterbalance the door's weight, simplifying the lifting process. 

In lever-based mechanisms like hand levers or foot pedals, these springs provide return force to bring the lever back to its original position, ensuring the mechanism remains responsive and reliable. From keeping hatches in place to enabling smooth operation of doors and levers, the diverse functionality of tension springs makes them an indispensable component in these applications.

Selection of Spring Materials

We manufacture tension springs predominantly using unalloyed spring steel and stainless spring steel. Tension springs using unalloyed spring steel have a permissible stretch length for dynamic loads at 40°C. Following this guideline, the relaxation (deceleration of power over time) remains within acceptable bounds for most applications. If, however, this temperature is surpassed or the springs are subjected to dynamic life demands (over 10,000 cycles), they shouldn't be loaded to the stated stretch length.

For springs made with stainless steel, the normal operating temperature that maintains acceptable relaxation values is 150°C. If springs made with this material are utilized in temperatures beyond this or subject to dynamic life demands, loading should also not reach the stated stretch length. Abiding by these rules will enhance the springs' longevity and overall lifespan.

Looking at Individual Tension Springs

Examine the categories of tension springs for more comprehensive information. Adjust the filters for the preferred wire diameter, free length, and spring force. Each product level offers a downloadable PDF taking you to our extension spring catalogue. Ensure you are satisfied with the springs' tolerances and suitability before finalizing your purchase. We would be more than happy to help if you require further information or assistance.

Custom Spring Options

At Lesjöfors Stock Spring US, we also design and create tailored extension springs. Share the specifications of your spring type, and one of our skilled team members will reach out to discuss and refine your requirements.

Ready to Order?

Our range includes diverse readily available options, all carefully designed to meet your specific needs. From our standard inventory of tension springs to our expertise in creating custom solutions tailored to your precise requirements, we have you covered.

If you can't find the perfect tension spring in our extensive catalogue, our dedicated team specializes in crafting personalized solutions for your unique application. Simply contact us, and one of our knowledgeable team members will contact you promptly.