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When equipment performance depends on precision, fatigue resistance, and reliability, using poorly engineered tension springs can lead to costly downtime or even system failure. At Coiling Technologies, we solve this problem by designing and manufacturing custom extension springs that meet exact specifications and perform in the most demanding conditions.
As an experienced extension spring manufacturer, we partner with engineers and OEMs to deliver durable, high-performance spring solutions across industries ranging from automotive to aerospace.
Performance of Custom Extension Springs
Extension springs are designed to absorb and store energy while creating resistance to a pulling force. Typically attached at both ends to components, these helical extension springs work by drawing assemblies back together when the connected parts move apart.
Coiling Technologies produces industrial extension springs that combine advanced design with precision manufacturing to ensure consistent force, repeatability, and long service life. From heavy-duty extension springs for large mechanical systems to lightweight options for precision devices, we build springs that meet your application’s specific load and performance requirements.
Collaborative Engineering and Design Process
Our experts collaborate closely with your engineering and procurement teams to create extension springs tailored to your requirements. Each design balances material properties, geometry, and load expectations to achieve optimal performance.
We work with you to:
- Assess operating conditions, service life, and load requirements
- Define physical dimensions, body shape, and free length
- Engineer end configurations such as loops, hooks, or custom interfaces
- Select the ideal material to meet mechanical and environmental demands
The result is a spring design engineered for consistency, reliability, and durability—even in the harshest environments.
Applications for Extension Springs
Our custom extension springs are engineered for industries where performance and reliability are non-negotiable. Applications include:
- Automotive parts and automotive aftermarket springs
- Garage door assemblies
- Hoisting systems and lifting equipment
- Vise-grip pliers and hand tools
- Trampolines and recreational equipment
- Washing devices and industrial machinery
- Farm equipment and agricultural machinery
- Medical devices requiring precision components
- Porch swings and consumer products
- Pool cover mounts and specialty fixtures
For OEM manufacturers, we supply large extension springs in bulk quantities, ensuring consistency across production runs.
Design Parameters and Capabilities
At Coiling Technologies, our manufacturing flexibility allows us to produce extension springs in almost any dimension, with multiple end types to suit your application.
Specifications include:
- Free length: Measured in the unloaded position from inside the end loops; can be cut to custom length for specific load requirements
- Body length: Up to 72 inches (1.8 m)
- Wire/bar diameter: Up to 2.50 inches (65 mm)
- Hook length: Adjustable for precise load at any extended position
- End types: Hooks, threaded inserts, extended twist loops, crossover center loops, expanded eyes, reduced eyes, rectangular or teardrop-shaped
This flexibility allows us to design heavy-duty extension springs for large mechanical loads or smaller-scale components for precision assemblies.
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Extension Spring Materials
We source only the highest-grade raw materials, meeting and exceeding OEM standards. Material selection is critical to spring performance, and we offer a wide range to address corrosion resistance, fatigue strength, temperature limits, and weight reduction.
Carbon Steels
- Hard Drawn Wire ASTM A227, ASTM A764
- Music Wire ASTM A228
- Oil Tempered Wire ASTM A229
- Chrome Vanadium ASTM A231, ASTM A232
- Chrome Silicon ASTM A401, A877, A1000, SAE 9254
- SAE 4160, SAE 4340, SAE 5160
- European grades 51CrV4, 52CrMoV4
Properties: Economical, strong, ductile, suitable for temperatures up to 450°F (232°C), with excellent fatigue resistance.
Stainless Steels
- 17-4 ASTM A564
- 17-7 Stainless ASTM A313, AMS 5678F
- 302 and 316 Stainless ASTM A313-18
Properties: Excellent corrosion resistance, reliable tensile strength, widely used for outdoor and marine environments.
Super Alloys & Nickel Alloys
Properties: Exceptional resistance to corrosion, oxidation, and high temperatures. Ideal for aerospace, petrochemical, and high-heat industrial applications.
Cobalt-Nickel Alloys
- Elgiloy, Haynes 282, MP35N, Nimonic 90, Rene 41, Waspaloy
Properties: High strength and resistance to sulfide stress cracking. Common in aerospace and energy applications.
Nonferrous Alloys
- Phosphor Bronze ASTM B159-17
- Beryllium Copper ASTM B196-13
Properties: Nonmagnetic, highly corrosion-resistant, and excellent for electrical applications.
Extension Spring FAQs
What is an extension spring?
Extension springs are mainly designed to store and release energy, providing a resisting force that will gradually increase while the spring is extended. Extension springs design and configuration allow it to operate under tension, while compression springs are used under compression.
What are extension springs' most common applications?
Extension springs typical applications:
- Garage doors.
- Automotive industries.
- Heavy machinery.
- Farm and agricultural equipment.
- Trampolines and recreational equipment.
- Medical devices.
- Household equipment like washing machines.
- Vise-Grip and hand tools.
What types of end/hooks are available?
Common ends/hooks as follows:
- Machine loops.
- Cross-over center loops.
- Side hooks.
- Extended hooks.
- Threaded insert blocks.
- Custom-made hooks.
What are the main causes of extension spring failure?
All springs are subject to failure if the design and capabilities are exceeded. The most common reasons are as follows:
- Excessive overload.
- Misalignment during installation.
- Exposure to corrosive environments and high temperatures.
- Improper design not suitable for the end application.
- Excessive cycling combined with high temperature and corrosive agents.
Still have questions? Contact our engineering team now. We can answer any question related to extension springs!
Why Choose Coiling Technologies?
With over 45 years of experience, Coiling Technologies stands apart from other automotive spring manufacturers and competitors by offering:
- ISO 9001:2015-certified manufacturing for consistent quality
- Expertise in exotic alloys like Rene 41 and Inconel for extreme environments
- Advanced processes, including prototyping, stamping, wire forming, powder coating, magnetic particle inspection, cycle testing, and heat treating
- The flexibility to manufacture large extension springs and bulk production orders without sacrificing precision
Our goal is to be more than a supplier. We are an engineering partner that helps clients solve technical challenges and achieve performance goals.
Request a Quote or Contact Us
If your project requires precision-engineered custom extension springs, Coiling Technologies has the expertise, capacity, and material selection to deliver the solution. From industrial extension springs for large-scale equipment to corrosion-resistant designs for marine or medical use, our team is ready to build springs to your exact requirements.
