Since 1850, John Evans’ Sons has manufactured springs for many unique devices and applications. We’ve manufactured suspension components for the Mars Rover Curiosity, counterbalancing mechanisms for M1A1 Abrams Tanks, and more. It’s common for us to manufacture a custom spring assembly for our clients’ proprietary devices, but we also have a selection of stock springs that can be useful at the prototype / developmental stages of a project.

A few of the types of springs that we manufacture at John Evans’ Sons include constant force springs, spiral torsion springs, and power springs. If you’d like to learn more about any of these products and which is best for your application, please reach out to our engineering team.

Smooth Range of Motion: Constant Force Springs

Constant force springs provide a smooth range of motion and constant load, meaning they do not follow Hooke’s law. They are uniform in length and coiled into a permanent diameter.

Constant force springs are frequently used for applications that require counterbalancing, including windows. In fact, window balance springs are one of our most successful products.

In addition, the springs we manufacture are often designed for medical devices and aerospace applications. Their smooth range and steady motion control enhance instrument articulation.

High Torque with Little Rotation: Spiral Torsion Springs

Spiral torsion springs are another popular product we manufacture at John Evans’ Sons. These springs are ideal for applications that require high torque and less than 360 degrees of rotation. (270 degrees maximum is preferred).

Spiral torsion springs are commonly used in applications that require a “return to center” function, like a medical instrument joystick. They’re also ideal for electric motors and automotive applications. If your application requires this “return to center” function, developing a custom spiral torsion spring may be the best solution.

Torque with Significant Rotation: Power Springs

Power springs (also referred to as clock springs) are appropriately named due to their rotational energy that takes the form of torque. The torque increases as the spring is wound tighter. They are wound around an arbor or shaft and are retained in a housing.

Their large rotation capabilities make them an ideal spring for a number of automotive applications or medical devices. Power springs are also frequently used for counterbalance mechanisms in industrial sectors.

Custom vs. Stock Springs: Which are Best for You?

As you begin to develop a concept regarding what type of spring(s) you’ll need for your device or application, you’ll want to begin to weigh the benefits of custom versus stock springs. A quality contract manufacturer should be able to offer both options, but they should also be able to tell you which is best for your application. John Evans’ Sons has custom and stock springs available for the products mentioned above.

A custom spring or assembly may be better when you require exact dimensions for your design. A stock spring will likely be an approximate fit.

On the other hand, a stock spring could be ideal if you need a quick turnaround. This type of spring can lower costs if you don’t require customization.

However, both types of springs are cost-effective, as long as you’re choosing the one that best fits your device. In some instances, custom springs are actually the more cost-effective option because you’re getting exactly what you need the first time.

Many companies select John Evans’ Sons for our custom design capabilities, which include our fully staffed and equipped, in-house tool-making department. Other companies choose us for the convenience of our stock spring selection.

Have further questions about these products and our manufacturing capabilities? Reach out with product requirements or to request a quote.