High Tensile Strength | Long Fatigue Life | Stable Performance
Our Carbon Steel Extension Springs are precision-engineered to provide exceptional tensile strength, long-lasting fatigue resistance, and consistent performance across a wide range of applications. Made from high-quality carbon steel, these springs are designed to withstand repeated stretching and dynamic loads while maintaining their original shape and elasticity.
Unlike standard extension springs, our carbon steel variants offer enhanced durability and stability, making them suitable for high-stress mechanical and industrial environments. They are manufactured with precision coiling and optional surface treatments, such as zinc plating or black oxide, to improve corrosion resistance and prolong service life.
These springs are ideal for applications where reliable load control, consistent force, and durability are critical, including automotive, industrial machinery, electronics, and mechanical assemblies.

High Tensile Strength for heavy-duty applications
Long Fatigue Life to withstand repeated stretching cycles
Stable Performance under dynamic loads
Precision Manufacturing ensures consistent dimensions and force
Optional surface treatment for corrosion resistance
Customizable dimensions, hook types, and material specifications
| Parameter | Specification |
|---|---|
| Spring Type | Carbon Steel Extension Spring |
| Wire Diameter | 0.2 – 12 mm (customizable) |
| Outer Diameter | Customized according to design |
| Free Length | Customized |
| Hook Type | Closed Loop / Open Loop / Custom |
| Spring Rate | According to customer requirement |
| Material | High-quality Carbon Steel |
| Surface Treatment | Plain, Zinc Plated, Black Oxide |
| Maximum Load | Customized based on application |
| Working Stroke | Customized |
| Tolerance | According to DIN / ISO / Customer Spec |
| OEM / ODM | Supported |
Carbon Steel Extension Springs are widely used in industrial, automotive, and consumer applications where tensile strength, stability, and durability are essential. Common applications include:
Automotive components: throttle return springs, brake assemblies, seat mechanisms
Industrial machinery: levers, actuators, tension control systems
Electronics: switches, connectors, relays, and protective mechanisms
Mechanical assemblies: doors, locking mechanisms, vibration control
Consumer products: appliances, tools, and fitness equipment
Their reliable force control and long service life make them ideal for repeated use in dynamic or high-load environments.
We provide full OEM and ODM customization services:
Wire diameter, outer diameter, free length, and hook design
Spring rate and working stroke based on load requirements
Surface treatment and corrosion resistance for specific environments
Material selection for enhanced strength or specialized applications
Prototype development and performance testing
Our engineering team works closely with clients to ensure optimal spring performance and cost-efficient production.
Design consultation and engineering support
Rapid prototyping and sample approval
Stable mass production with strict quality control
Technical documentation and inspection reports
Responsive pre-sales and after-sales support
Individual or bulk packing options available
Inner plastic bags with outer cartons or wooden crates
Customized packaging upon request
Worldwide shipping via air, sea, or express courier
Secure packaging to prevent deformation during transit
Q1: Can you manufacture according to drawings or samples?
Yes, we can produce extension springs based on customer drawings, samples, or technical requirements.
Q2: What are the advantages of Carbon Steel Extension Springs?
They provide high tensile strength, long fatigue life, and stable performance, making them ideal for repeated and heavy-duty applications.
Q3: What materials are available?
We mainly use high-quality carbon steel, with optional surface treatments such as zinc plating or black oxide. Special alloys can be provided on request.
Q4: Can you customize spring dimensions and hook types?
Yes. All dimensions, coil diameters, hook designs, and spring rates can be customized according to customer requirements.
Q5: What is your MOQ?
MOQ is flexible and depends on the spring design and production process. Contact us for details.