While working on engineering designs, you'll often need to select fitting extension springs. Seen in wide-ranging uses from trampolines to large machines, understanding the production processes and selection guidelines for these springs can be helpful. Imagine a scenario as a robotics engineer requiring springs for a robot's limb. If the springs are too stiff, you would witness inflexible movement; too soft, the limb may face issues handling weight. With a clear comprehension of extension spring production and choosing methods, you can make more effective spring choices for your tasks.

COTS Spring Manufacturing Process

The Commercial Off-The-Shelf (COTS) extension springs manufacturing procedure comprises several distinct stages. The process begins by selecting a suitable metal for the spring. This choice often depends on factors such as required strength and anticipated operating environment. Frequently, steel is the metal of choice due to its high-tensile strength. However, in scenarios where the environment might be corrosive, stainless steel would be an optimal selection. The chosen metal is then transformed into a wire. The diameter of this wire is determined by the intended use of the spring.

The second step involves coiling the wire around a mandrel to achieve a cylindrical shape. The coiling process can be executed using either a hot or cold method. The method chosen is reliant on the physical properties of the metal and the intended spring application. It is generally observed that cold coiling is suitable for thinner wires, while higher temperatures are used for wires of greater thickness or with lesser flexibility.

Heat treatment concludes the process. This stage is essential to reduce the stresses produced during the coiling process thereby increasing the longevity of the spring. The parameters for this treatment are conditioned by the expected application temperature and the specific characteristics of the utilized metal. This systematic approach ensures the production of extension springs that are fit for diverse applications.

Custom Springs

Custom springs are designed to match distinct needs not met by readily COTS springs. The design occurs through a joint effort between the customer and the engineering team to ensure the spring aligns with the required application.

The creation of custom springs takes into account certain variables such as wire diameter, quantity of coils, spring ends style, and the spring's form. For example, an application undergoing high-stress might need a larger wire diameter to prevent material deformation, increasing the spring's lifespan and the application's safety.

In custom spring design, appropriate material selection is also a factor and depends on the spring's operating environment. A corrosive environment might require a material able to resist corrosion, such as stainless steel.

Custom springs, while providing several benefits, may also extend the time for design and manufacturing due to their distinct nature. Similarly, the cost might increase due to specific materials or production methods required. Balancing these elements supports the design and selection process, resulting in the most suitable spring for the required application.

Spring Selection

The function of the spring in your device aids in determining the type of spring that should be used. If we consider a scenario where the spring is part of an automatic gate mechanism for the storage and release of energy, properties like stiffness and elasticity have a key role in the design.

The operating condition of the spring is a vital aspect of spring selection. If the device, like an outdoor gate mechanism, is exposed to varying weather conditions and corrosive elements such as road salt in winter, a stainless steel spring, coated for resistance against corrosion would be a suitable choice.

Physical characteristics such as the dimensions, shape, and load range of the spring are additional factors, which must align with the space and operation requirements of the application. In an application with a small mechanical compartment like an automatic gate, the spring's dimensions need to be appropriate and the load range should be sufficient for the weight of the gate sans deformation.

In terms of sales of extension springs, cost-effectiveness and demand are relevant. Good engineering practices involve considering client needs in tandem with design choices to ensure durability and cost-effectiveness.


Extension springs are used widely in different applications. The production of pre-made springs can be intricate, and grasping this can aid in selection. Yet, custom springs offer distinct advantages and can better fit specific project needs. To choose springs, you should ascertain their use, the environment in which they'll operate, and any dimensional limitations. Acknowledging these points will improve the durability and functionality of your springs. An in-depth understanding of these aspects simplifies the extension spring sales process, and helps in making accurate choices.