Stretch spring manufacturers and customized stretch springs
We are an excellent manufacturer and supplier of stretch springs. Keneng Heli specializes in designing and manufacturing various sizes and specifications of inventory and customized tension springs. We have excellent manufacturing capabilities and can provide various materials, sizes, end types, lengths, spacing configurations, surface treatments, and optional certifications. In addition to customizing tension springs according to your drawings and requirements, we also have a large number of standard tension springs available.
As a Chinese manufacturer of tension springs, we have senior technical personnel with years of experience in spring production to design customized springs for you. We also have various testing equipment to assist in spring production. We are doing our best to help you reduce the cost of using spring parts, while also focusing on improving product quality, stability, and assembly efficiency.
Heavy duty and durable tension spring
Stretching springs, also known as closed coil springs, are connected at both ends to different components. When external force is applied, the components will separate and these springs will attempt to pull them back to their original positions. That's why these springs are sometimes referred to as tension coil springs. For this purpose, the tension spring absorbs and retains energy. The resistance it generates is equal to the applied force. Heli Spring offers closed wound tension springs with different functions and specifications. These springs are made of circular spring steel materials of various grades and alloys. Stretch springs can be configured in various hook shapes, including mechanical hooks, German hooks (shaft cut or extended piece), English or cross center hooks (as shown below), and side or edge hooks.

The measures for defining tension springs are as follows:

Lt=total length of the spring at rest
Lc=length of the spring body
De=outer diameter
Di=inner diameter
H=wire diameter
Total number of laps
Spiral direction (if not specified, manufacture arbitrarily)
Hook types (British, German, rotary, open, closed, double...)
The position of the hook (cross, straight, etc.)

Stretch springs have various ring structures, each with different functions. These springs are widely used in daily applications, from garages to cars, toys, electronic products, and more.
The following are some common applications of tension springs in daily life:
Automotive use
Stretch springs are used both inside and outside the vehicle. Although the use of tension springs has decreased in modern cars, they were once key components in vehicle carburetor systems.
garage door
Stretch springs are commonly used for garage doors, installed on both sides of the garage door to assist in its movement. These springs help reduce the force required to open and close garage doors.
Trampoline spring
Trampolines rely on stretching springs to provide bouncing effects. The bottom spring allows users to easily bounce back and continue jumping. The more springs there are, the stronger the bouncing force.
Toy applications
Stretch springs are widely used in toys, especially those involving projectile motion, such as toy guns and cars. For toys with fast movement or throwing movements, tension springs are essential.
vise
The tension spring in the vise ensures a secure grip on the object, once clamped, it can be firmly locked in place.
washing machine
In washing machines, tension springs are crucial for stabilizing the rotating drum. They help ensure that the drum remains stable and does not collide with the side of the machine, thereby preventing excessive noise.
medical equipment
Stretch springs are used in various medical devices, such as stretchers, surgical lights, and various instruments, to provide necessary mechanical functions.
Agricultural equipment
Stretch springs are used in agricultural equipment such as harvesters, tractors, and plows to assist in completing heavy tasks and improve agricultural work efficiency.
stroller
The tension spring in the stroller allows the stroller to sway back and forth gently with minimal force, providing a smooth and soothing motion for the baby.
Fence Gate
The tension spring in the fence door enables the fence door to automatically close after opening, thereby enhancing convenience and functionality.
Magazine spring
The magazine spring provides the tension required to push the bullet into the firearm magazine firing chamber, thereby achieving fast and reliable feeding. These springs are made of high carbon steel and can withstand repeated use without losing strength.
recoil check spring
The recoil spring is located inside the bolt of an automatic or semi-automatic firearm and can absorb the impact force generated when the bullet is fired. This helps reduce the recoil felt by the shooter, making the shooting experience more comfortable.