What’s the Difference between compression spring and extension spring

What’s the Difference between compression spring and extension spring

Spring is generally made by winding spring wire, because of its simple production, low price, easy to detect and install, so it is widely used. They are designed to store mechanical energy while stretching.  When a stainless steel spring is stretched, it will uncoil. Even when just partially uncoiled, a spring will store this mechanical energy. There are many different types of springs, however, two of the most common types are compression and extension. While they both store mechanical energy, they differ in several ways.

What Is a Compression Spring?

Wave springs are a type of compression spring made of flat wire with waves added to each turn of the wire.  Springs that resist axial compressive forces are categorized as compression springs.When force is applied to a compression spring, it compresses, or shortens, and stores energy. As the spring tries to return to its original length, it releases this energy and “pushes back” against the load. This shock absorber relies on compression springs to return to its extended position after each cycle. Compression spring is one of the most common types of springs and one of the most efficient at storing energy.          


What Is an Extension Spring?

Also known as a tension spring, a small tension spring is intended to operate under a load that creates tension.  As shown in the adjacent image, they typically feature a hook or loop on each end. To use an extension spring, you must attach the ends to two components. High tension springs are available in different sizes and materials, but they are all designed to extend under a load. If the components try to pull apart from each other, the extension spring will force them back together.

1. Working Principle

A compression spring is used to shorten its length under an external force. Compression spring will push the structural member to increase its length. An extension spring is meant for increasing its length under the action of external force.

Compression springs wire are designed for use in applications where two components try to push towards each other. To prevent the components from making contact, a compression spring may be used. The compression spring is placed between the two components where it compresses. As the two components try to push towards each other, the compression spring will compress. In turn, it will store mechanical energy that subsequently pushes the components back out.

Tension springs and compression springs aren’t the same. Extension springs are intended for use when two components try and pull away from each other. In comparison, compression springs are intended for use when two components try and push towards each other.

2. Basic parameters required for design

Compression springs and extension springs differ in their design, which depend on the basic parameters. For example, inner diameter, outer diameter and length.

● Spring Force. It’s vital to know the actual force required while the spring is in the working state, so as to decide the compression, wire diameter and compression spring material. The compression stroke determines the number of turns.

● Required tension, that is, the weight that can be loaded, determines the material, wire diameter and adjustable length of the Extension spring.

● Space range, knowing the space range, you can determine the outer diameter, free length and winding times of the Extension spring.

Xulong provides design assistance and our technical department utilize CAD to make drawings of springs. With over 40 years of experience in spring field, we are confident that our colleagues of technical department can be of help to design your unique springs.

3. Shape

For the compression spring, the compression spring is used under the pressure of the coil spring, and the material used in it is mostly circular in cross section. It is also useful to have a stroke made of rectangular and multi-strand steel. The spring is usually It is for the pitch. When the amount is large, the compression spring has a certain gap between the circle and the circle. When the spring shrinks and deforms under the action of external load , Deformation energy storage. For example, the shape of the compression spring is: cylindrical, conical, convex and concave, and a small non-circle.

For Extension spring, Extension spring is a coil spring under axial tension. For Extension spring, it is usually made of circular cross-section material. In the case of no load gravity, the tension between the coil springs is usually very tight, and there is no gap between the rings.

4. Working environment

● The surface of the spring should be treated to avoid corrosion and moisture if it works in a high humidity environment, which can make compression spring life last longer.
● High temperature R. Electrostatic material should be selected if it works in a high temperature environment because temperature affects the service life of spring a lot.


Whether it is compression springs or extension springs, they are all indispensable and widely used component in the economic society and industrial society, which promotes the steady development of social economy. XULONG SPRING is one of the
Stainless steel spring suppliers in China and we provide customized springs and wire forms,we have been digging in spring field since 1979, the dedicated work attitude and persistent endeavor of Xulong staff guarantee quality product, thoughtful service and on-going create maximum value for the users.