EN
The tension mainly depends on wire diameter, outer diameter, active coils and raw material. Thicker wire and smaller outer diameter create stronger tension.
Tension springs, also known as extension springs, are cylindrical coil springs that generate restoring force through tensile deformation, mostly wound from round-section metal wire. Under no external load, all coils are tightly closed without gaps, with various end hooks such as full loops, reduced diameter hooks and extended hooks for connection and fixation with matching parts. When subjected to axial tension, the coils stretch to produce elastic deformation; once the load is removed, the springs return to their original shape relying on material elasticity, delivering functions including resetting, pulling, energy storage and shock absorption.
Available materials cover carbon spring steel, stainless steel and alloy spring steel. Stainless steel versions feature excellent rust and corrosion resistance for humid and corrosive environments, while carbon steel springs boast cost performance for ordinary room-temperature equipment. Thanks to simple structure, stable spring force and easy installation, tension springs are widely used in hardware, mechanical equipment, medical devices, stationery, auto parts and home appliances. They can be found in small items like scissors and tape measures as elastic components, as well as traction and limit parts for large industrial machinery. Customization on wire diameter, outer diameter, active coils, hook size and tensile strength is available to meet diverse load requirements of different working conditions.
End Shape Design
Machine (Twist) Loops • Crossover Center Loops
Side Loops • Extended Hooks • Crossover Center Hooks
Rectangular Ends • Teardrop Ends • Threaded Inserts
Finishing Operations
Stress Relieve • Heat Treating • Passivation
Painting • Plating
Wire sizes from 0.1mm through 16.0mm
Materials
Carbon Steels • Alloy Steels
Stainless Steel 17-7, 302, 304 and 316
Phosphor Bronze
Inconel x750
Extension springs are utilized across almost every industry, particularly in applications requiring precise force at a specific deflection. Yisen specializes in custom manufacturing services for extension springs—whether you need extra-long dimensions, high-performance capabilities, or quality-certified products, we provide a full range of solutions.
Our solution services go far beyond the manufacturing phase. We also specialize in prototyping, product design, and tooling development. We will work closely with your team to help develop the ideal spring product that perfectly fits your application requirements based on your specified technical parameters.
Tension springs are widely used in machinery, electronics, automotive and household appliances, providing stable tensile force and reliable reset function for all kinds of mechanical structures.
Specialized extension springs with crossover center loop structure for centered tension distribution. Prevent offset deflection, ensure smooth stretching and stable pulling force. Suitable for fitness equipment, mechanical tensioning structures, industrial stretching devices. Customizable.
Heavy-duty drawbar-style extension springs with stable linear tension and ultra-low deflection. Rigid structural design, excellent tensile strength and long cycle lifespan. Widely used in industrial drawbar systems, mechanical tension equipment, agricultural machinery and automotive devices. Customizable.
Standard extension springs with elongated extended hooks for versatile mounting and easy assembly. Features even stress distribution, stable tensile force and long fatigue life. Perfect for hardware fittings, automation equipment, fitness machinery and general industrial tension applications. Customizable.
Built with standard machine loops at both ends for standardized mechanical assembly. Features stable tensile force, firm connection and great fatigue resistance. Ideal for general machinery, conveyor systems, industrial tools and transmission components. Customizable.
Featuring integrated side loops and side hooks for flexible installation and firm positioning. Uniform stress distribution, outstanding tensile strength and stable performance. Ideal for general machinery, hardware assemblies, automated equipment and industrial fixtures. Customizable.
Designed with rotatable swivel hooks to avoid torsion during operation. Uniform tension, flexible installation and great fatigue resistance. Ideal for conveying equipment, amusement facilities, general machinery and hardware assemblies. Customizable.
Tension springs are indispensable basic elastic components in automated production lines and conveying systems, widely used in roller conveyors, belt assembly lines, pneumatic manipulators, tooling fixtures and automatic sorting equipment. In belt conveying systems, tension springs provide constant axial tension for tensioning devices, offsetting the relaxation deformation of belts during long-term operation, preventing slipping and deviation, and ensuring conveying accuracy and stability. In pneumatic manipulators and fixtures, they provide rapid reset force and clamping auxiliary force to achieve precise grasping and release of workpieces. They are also used in automatic closing mechanisms of various limit switches and safety doors, improving the safety and automation level of equipment operation.
Tension springs play core roles of resetting, tensioning, buffering and sealing in household appliances, covering almost all common home appliance categories. In washing machines, the door cover safety lock tension spring ensures that the door cannot be opened during the dehydration process and realizes automatic closing of the door cover. The tension springs built into refrigerator door seals provide uniform tension, making the door closely fit the cabinet and improving the thermal insulation effect. The door hook tension springs of microwave ovens and ovens ensure the door is locked and sealed to prevent microwave leakage. They are also used in printer paper feeding mechanisms, vacuum cleaner brush head lifting, electric fan head shaking reset and other scenarios, ensuring the functional stability and use safety of home appliances.
Tension springs are standard supporting components for various hand tools and furniture hardware, directly affecting the use feel and service life of products. In the field of hand tools, scissors, garden shears, wire cutters, needle-nose pliers and other tools are equipped with built-in tension springs to realize automatic opening of blades or jaws, greatly improving operation efficiency and reducing hand fatigue. In furniture hardware, the hinge mechanisms of folding tables and chairs and sofa beds use tension springs to provide auxiliary force, making folding operations more convenient. The buffer tension springs of drawer slides can slow down the impact force when the drawer is closed, realizing silent closing. The lock tongue rebound mechanisms of door locks and latches also rely on tension springs to provide stable reset force.
Tension springs are core resistance and elastic support components of many fitness equipment, directly determining the sports experience and equipment safety. In strength training equipment, tension exercisers, arm strength devices and comprehensive training machines use tension springs of different wire diameters and turns to provide adjustable exercise resistance to meet training needs of different intensities. The peripheral suspension system of trampolines consists of multiple groups of high-strength tension springs, which evenly distribute elastic force and provide a safe and comfortable bouncing experience. They are also used in the tension mechanisms of rowing machines, shock absorption auxiliary systems of treadmills, lifting mechanisms of basketball hoops and other parts, with the characteristics of high fatigue resistance, stable elasticity and long service life.
