Tension springs, also known as extension springs, are helical wound coils that are wrapped together and operate with tension. Tension springs have hooks or loops that are attached to both ends. These hooks help in attachment to other components. Read More…
Leading Manufacturers
R & L Spring Company
Lake Geneva, WI | 262-249-7854R&L Spring Company manufactures custom spring and wire formed components for industries such as powersports, automotive, medical devices, and general industrial. Products include compression, extension, and torsion springs, as well as rings, wire forms, fourslide components, and long coils. Wire diameters available from .001" to .750" in both shaped wires and flat stocks. Their experienced team is able to meet the most demanding parts specifications. IATF16949 and ISO9001 certified.
All-Rite Spring Company
Spring Grove, IL | 815-675-1350All-Rite Spring Company specializes in quick-turn design, prototype, and manufacture of springs and wires of all shapes, sizes, and material types. Typical applications are: Automotive, Agricultural, Consumer Appliance, Industrial, Safety Critical, and other High Functional Value and/or Life Cycle.
Apex Spring & Stamping Corporation
Grand Rapids, MI | 616-591-9524Apex Spring & Stamping is a certified minority owned company that manufacturers springs, stampings, wire forms, clips, and fasteners. Our core industries include automotive, office furniture, medical, recreational, consumer goods, and appliances. We also specialize in value added assembly and prototyping. Our engineering team will ensure your part is both functional and cost-effective. IATF 16949 Certified.
Coiling Technologies, Inc.
Houston, TX | 713-849-4000Coiling Technologies, Inc. has the experience and expertise to design and engineer the custom springs to meet your specific requirements. We are a leading manufacturer of high-tech, specialized springs and we are committed to providing quality products with fast lead times. Our automated process allows us to produce the reliable springs you need.
Sterling Spring Corp.
Chicago, IL | 800-969-7884Sterling Spring has offered high-quality springs since 1953. Our product line includes compression springs, coil springs, torsion springs, extension springs and industrial springs. We offer just-in-time delivery and cost-effective prices, regardless of your ordering volume.
Diamond Wire Spring Company
Glenshaw, PA | 412-684-1201Diamond Wire Spring Company is a designer and manufacturer of precision springs. We have over 75 years of experience in stock and custom springs. Our founding principles of providing quality products and strong, personalized customer service help us earn the trust of our customers. We have more than 11,000 different springs available. We serve many industries including power and energy, agriculture and rail, and many others. Call us today!
Pa-Ted Spring Co., LLC
Bristol, CT | 860-582-6368Our springs are made of a variety of materials and can be used in many different applications. Pa-Ted manufactures custom designed springs for the automotive, electrical, medical, landscaping, pool covers, and original equipment manufacturers industries, and uses materials such steel, beryllium copper, music wire, brass, titanium, tungsten wire, oil tempered wire, and resistance wire. Call us for wire forms today!
When the tension spring is at rest, it's in its compressed form, but when an external force is applied, it is extended. This extension is resisted by the tension force created in the spring, which pulls back to the original position. The tension of the spring is determined by the load applied to it. The outside diameter, coiling, and wire diameter of the spring determine its tension.
How Tension Springs are Made
Tension springs are mostly made of metal, and their type depends on the amount of stress it is exposed to and other environmental conditions. The materials that are mostly used are:
- Copper Alloys
- Stainless Steel
- Spring Steel
- Titanium Alloys
- Low Alloy Steel
- Cold Rolled Steel
The manufacturing process of tension springs is done with highly-advanced hot and cold coiling procedures. The wire is bent, heat-treated, and finally finished or coated to protect the spring from corrosion or humidity. Tension coiling machines manufacture springs of dimensions between 0.004 to 1 inch (0.1 to 26mm).
Characteristics of Tension Springs
- Tension springs stretch and create a load.
- Tension springs have a little gap between the adjacent coils, and the load is applied along its axis.
- Tension springs are durable and designed with great precision.
- These springs have dimensional stability and high tensile strength.
Working of Tension Springs
A tension spring is a helical spring with tightly wound coils. These springs operate under applied tension. When the spring is at rest, no load is attached to its ends; the coils touch each other and are in a compressed shape. When an external force is applied, the spring stretches to a specific length. This means the components attached to spring ends pull them apart, causing tension in the spring. This makes the spring come back to its original position.
Lifespan of a Tension Spring
The lifespan of a tension spring depends on the following factors:
- Frequency of use
- Spring application
- Material of the spring
- The environment of the spring
- Amount of the stress that is applie
The lifespan of tension springs is mainly determined by environmental factors. Exposure to sunlight, chemicals, corrosive agents, and water affects the integrity of the metal. Continuous load exposure also causes metal fatigue in the springs, which causes microcracks in its structure.
Types of Tension Springs
Many types of tension springs depend on the type of hooks or loops attached to their ends. These loops differ from one another and depend on the application type. Some of these types are as follows:
Machine Hooks
Machine hooks are the most commonly used ones. It is the strongest of all the hooks because the bend radius is not pronounced. Bending ¾ of the coil can make machine hooks.
Cross-over Center Hooks
Cross-over center hooks are the second most commonly used hooks. The bent radius for these types of hooks is pronounced. These hooks are made by lifting the last coil and twisting it in the middle.
Side Hooks
Side hooks are ideal to use when body interference is not required during the mechanism. As the name suggests, the hook is on one side of the spring. These hooks are made by bending the last coil and are more economical than other types.
Extended Hooks
These hooks are the same as used in side hooks. These are useful when there needs to be a long length inside the hooks but a shorter body. The extended hooks are the most expensive type of hooks.
No Hooks
Tension springs with no hooks are the most economical ones. These are good to use as they are stress-free, and they have no trace of fatigue at the ends due to the non-presence of the hooks. Springs with no hooks have an increased pulling force and a higher lifespan for the spring.
Applications of Tension Springs
Tension springs are widely used in our daily life and industries. Some of their applications are:
- Trampolines
- Garage doors
- Toys
- Pliers
- Gardening equipment
- Weapons
- Carburetors
- Exercise equipment
- Fence gates
- Baby carriages
