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Extension Springs

A reliable source for Extension Springs information and leading Extension Springs Companies & Manufacturers.

Extension springs are helical wound springs that can be stretched for an increase in length. Because of the tension created in them due to extension, these are known as extension springs. Extension springs store mechanical energy and release it in the form of expansion. Each spring end is attached to the components. Read More…

Extension Springs Extension springs are coil springs that lengthen under the weight of a load.
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Leading Manufacturers

Lake Geneva, WI  |  262-249-7854

R&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.

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R & L Spring Company $$$

Spring Grove, IL  |  815-675-1350

All-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.

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All-Rite Spring Company $$$

Grand Rapids, MI  |  616-591-9524

Apex 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.

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Apex Spring & Stamping Corporation $$$

Houston, TX  |  713-849-4000

Coiling 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.

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Coiling Technologies, Inc. $$$

Garden Grove, CA  |  714-898-2666

For over 60 years, Bazz Houston International (BHI) has been recognized as a one of the best full service metals fabrication manufacturers on the West Coast. We manufacture springs, stampings, wire forms (up to 3/8”), fourslides, assembly, tooling, and metal fabrication. Our products are manufactured in Mexico and California in order to provide our customers shorter lead times, lower freight costs and no customs charges or delays. Our plants are ISO:9001 Registered for quality assurance. We serve the aerospace, automotive, defense, electronic, irrigation, lighting, and medical industries. Call us or visit our website today.

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Bazz Houston International (BHI) $$$

Monticello, IN  |  574-583-8090

Monticello Spring is a manufacturer that specializes in springs: compression springs, torsion springs and extension springs. We are QS 9000/ISO 9002 certified and a leader in the spring industry. Our commitment to total quality management (TQM) is the foundation for our success.

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Monticello Spring Corporation $$$
placeholder image R & L Spring Company All-Rite Spring Company Apex Spring & Stamping Corporation Coiling Technologies, Inc. Bazz Houston International (BHI) Monticello Spring Corporation

Spring Power Pages

Coil Springs

Coil Springs

A coil spring is an elastic element made of metal or heavy plastic in the form of curls or ringlets of round wire or cord that is wrapped around a cylinder. The winding of a coil spring can be loose or tight in a helical shape depending on the application for which it is made...

Compression Springs

Compression Springs

Coil springs called compression springs can store mechanical energy when they are compressed. These open-coiled, helical springs provide resistance to compressive loading. When these springs are...

Extension Springs

Extension Springs

Extension springs are helical wound springs that are so closely coiled together to create initial tension in the coils. This initial tension creates resistance against the force applied to its ends for extension. The initial tension helps determine how closely and...

These components are pulled apart, and the extension spring tries to pull them back together. Extension springs have a hook at both ends that helps in fastening. There are many types of spring ends, such as open hooks, extended hooks, side hooks, and double full loops.

Extension Springs

Materials Used for Extension Springs

Extension springs are generally cylindrical but can be customized according to one's needs. The most commonly used materials for manufacturing extension springs are:

  • High Carbon Steels

    High carbon steel contains a high amount of carbon and hardens in contact with heat. Other types are music wire, hard-drawn MB, and oil tempered MB.

  • Stainless Steel

    Stainless steel is ideal for manufacturing extension springs because these springs are economical, exhibit good corrosion resistance, and have good magnetic properties. Other types are SS302, SS304, and SS316.

    Stainless Steel
  • Alloy Steel

    Alloy steel is also a type of steel, but nickel, chromium, or molybdenum is alloyed to give hardness and rigidity to the material. Other types are oil tempered chrome vanadium and oil tempered chrome silicon.

  • Copper Alloys

    Copper alloy is well known in the spring industry as they offer excellent corrosion resistance and great electrical conductivity. Other types are phosphor bronze, beryllium copper, brass, Monel 400, and Monel K 500.

    Copper Alloys
  • Nickel Alloy

    Nickel is in high demand because it can be alloyed with any other element and exhibits good heat resistance. These are durable, strong, and can withstand harsh environments. Other types are Inconel 600, Inconel 718, Inconel X 750, Elgiloy, NiSpan C, and Hastelloy.

Manufacturing Process of Extension Springs

The manufacturing process of extension springs is quite simple, but some variations can be seen according to the type of spring being manufactured. The process consists of three steps:

  • Winding

    The first step is the spring winding, in which the spring is fed into the machinery to straighten it up and give it the desired shape. The other steps are:

    • The coiling is done by feeding the wire into a CNC machine to coil it into a spring.
    • The forming process is done by the forming machine, which has six to eight tooling sides that convert the wire into the desired shape.
    • The wire is then transferred into the CNC wire bender for bending.
    Winding Machine
  • Heat Treating

    Heat treatment is the stress-relieving process when the spring is sent to the heated conveyor belt. In the oven, the wire is heated for a maximum time and temperature. The heated spring is then sent to the receiving box for cooling.

    Heat Treating
  • Coating and Finishing

    The last manufacturing step is the coating and finishing of the springs. The spring is coated with different materials to give durability, heat, and corrosion resistance to the spring. The coating is done by shot peening, powder coating, and plating.

Types of Extension Springs

Extension springs are categorized based on end types or hooks attached to them. The hooks or spring ends are designed according to the type of application they are used in. However, customization of hook types is also available. Some of the types are as follows:

Machine and Crossover Center Hooks

  • These are the most common types of extension springs.
  • The machine hooks are directly formed from the spring and then circle across the spring end center.
  • These are stronger than crossover center hooks because of the smaller bending radius.
  • The crossover center hooks are bent across the center, forming a circle on the end.

Side and Extended Hooks

  • These are more economical than crossover hooks and are formed by bending the spring's last coil.
  • This bending offsets the spring and provides tension.
  • Both extended hook and side hook are similar in use, but the difference is that the bending happens with a gap, giving a shorter coil body.

Double-loop and No Hooks

  • The double-loop end has two coils without a gap between the coil and the end of the wire.
  • This prevents spring breakage and gives more strength to the spring.
  • The spring with no hooks has no stress and fatigue on its ends.
  • It is more economical, has a better life cycle, and has a good pulling force.
Types of Extension Springs

Applications of Extension Springs

Extension springs are widely used in our daily life. There are a variety of functions that these springs offer. Extension springs are used in automotives, medical equipment, washing machines, pliers, toys, garage doors, trampolines, farming equipment, baby carriages, fence gates, and many more products.

Extension Springs Informational Video

 

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