Spiral torsion spring. John Evans’ Sons is a leader in development of custom spiral torsion springs for your application.

John Evans’ Sons is an industry-leading provider of custom spiral torsion springs designed to meet the needs of a broad range of applications. Utilizing materials such as stainless steel, specialty alloys, and carbon steel, we develop these springs to deliver significant torque with minimal rotation. We offer several spiral torsion mounting methods to provide ideal results for various settings. 

Learn about spiral torsion springs, including how they are manufactured, their benefits across various applications, and more.

What Is a Spiral Torsion Spring, and How Is It Manufactured?

When a spiral torsion spring is wound, it creates a concentric spiral. This mechanical device can store and release energy by exerting rotational torque force. The torque available per revolution is linear for the first 360 degrees. If the deflection is greater, the coils often “close out” or come into contact with each other, causing the torque to rise rapidly. 

They can provide significant torque in a short rotation. The short rotation is caused by the torque curve being linear to the degree of rotation. This design enables the springs to store more mechanical energy than extension, compression, or other helical springs. Spiral torsion springs are manufactured using flat types of steel and are best suited for operation in confined spaces. 

At John Evans’ Sons, we can accommodate any custom specification or configuration required, including but not limited to hooks, tabs, holes, and fasteners.


Various materials, including carbon steel, stainless steel, and specialty alloys, are available for spiral torsion spring development projects or prototypes. Each metal provides the following distinct advantages:

  • Carbon Steel: Widely used for engineering springs, carbon steel may require pre-galvanized coatings or additional corrosion protection.
  • Stainless Steel: Stainless steel exhibits excellent heat and corrosion resistance properties and is an essential metal alloy for manufacturing spiral torsion springs.
  • Specialty Alloys: Metals such as chromium alloys and cold-drawn nickel are best suited for applications requiring high corrosion resistance when exposed to extreme temperatures.

Spiral Torsion Spring Mounting Methods

Mounting methods vary based on the type of spring and can include the following:

  • Back-to-Back Mounting: Considered the most stable mounting method, back-to-back mounting features two springs attached back-to-back, allowing them to unwind in opposite directions. The configuration prevents twisting and is ideal for applications with long extensions.
  • Tandem: One spring is placed behind another, leaving a small space between the two devices. This mounting method is not as stable as other methods, so it’s best suited for applications with limited space for back-to-back mounting.
  • Laminar: The laminar mounting method interwinds multiple springs, creating an optimal solution for working in confined spaces. Laminar mounting takes up less space than a singular spring and can offer more force from the shorter extension.
  • Cavity: A low-cost alternative, cavity mounting is easy to assemble, as it does not require bushings, but friction can be a limiting factor. The spring gets mounted in a cavity, where it encounters constant contact and friction during movement. A cavity-mounted design must incorporate additional considerations to address this issue.


Spiral torsion springs are used in motion applications that require short rotation (less than 360 degrees). They achieve a large amount of torque through a small amount of rotation and are widely used in the following industries and applications:

  • Medical Devices
  • Aerospace/Defense
  • Industrial
  • Electric Motors
  • Trucking


Flat spiral torsion springs offer a wide range of advantages. These mechanical devices are extremely durable and long-lasting, providing good value for their cost. They are also easy to use and adjustable for use in vehicles and other applications. They are relatively small, allowing them to fit in various settings, especially those with limited space.

Need Assistance? Consult our Technical Team.

Our technical team offers a depth of expertise to assist you with all parts of the process. We are ready to answer your questions in a timely manner and will help you define what you need. We produce custom springs for all purposes, and we are here to work with you on any of your customization needs.

Contact us or request a quote to see what John Evans’ Sons can do for you.