Torsion springs are a type of helical spring capable of storing and releasing angular energy or holding a mechanism in place. They are characterised by two legs that extend from either end of the coil and are used in applications requiring a torque or rotary force. This is achieved by attaching the legs to external components. Then, as those components rotate around the spring, it attempts to push them back to their original position.

Torsion springs come in a myriad of different shapes and sizes, with varying leg configurations and lengths for use in a wide range of applications. Typical uses include car door handles, garage doors, clothes pegs, bulldog clips and hinges. In some instances, a single torsion spring cannot exert enough force. In these situations, a double torsion spring may be required.

double torsion spring

What is a Double Torsion Spring?

The defining feature of double torsion springs, as the name suggests, is that they are comprised of two torsion spring coils which are connected in the centre to form a single spring. The two coils are wound from a single piece of wire in opposite directions, with one wound counter clockwise and the other clockwise. These two sections work in parallel to one another, and like with single torsion springs, the legs will typically be pressed against the external component, allowing them to push back and create resistance. A shaft or rod usually runs through the centre of the bodies of the two coils.

Double torsion springs are stronger than their single counterparts and can exert a greater force. The force generated is equal to the force generated by the two individual springs combined. The bridge that joins the two coils together and the legs can be made to various lengths and shapes, depending on the application. In some cases, the bridge between the two coils will be tiny and simply there to minimise friction between the two coils. But it can also be large, forming a wide arch between the two coils. The spring design depends entirely on the intended use for the spring.

close up of different springs

What are Double Torsion Springs Used For?

There are many different applications that use torsion springs, and double torsion springs are no different. They are best suited for applications in which the spring will be required to assist in lifting or rotating and to neutralise and centre rotating loads. A double torsion spring should be used if the element requires two identical torsion springs wound in opposing directions. This type of spring sees widespread use in the medical industry, aerospace, military applications and even in household appliances.

How is a Double Torsion Spring Made?

As a leading spring manufacturer, we make double torsion springs much in the same way we do single torsion springs, with our state-of-the-art CNC coiling machines. These machines are capable of forming both right and left-handed coils, making them well suited for making double torsion springs. To ensure every spring meets the exact specifications required, the CNC machines are pre-programmed by one of our talented engineers.

cnc machine for torsion springs

Before a double torsion spring can be made, some information must be determined to ensure the finished product is suitable for its given application. This includes:

  • The wire diameter
  • Outer diameter (from the outside edge of one side of the coil to the other outside edge)
  • Inner diameter (from the inner edge of one side of the coil to the other inside edge)
  • The total number of coils requires for both springs
  • The shape and size of the bridge between the two coils
  • Leg length and angle
  • Leg ending type (e.g., bent, straight, hooked)
  • The size of the hole or shaft the spring will be fitted into/onto
  • The intended use for the double torsion spring

The more information you can provide about the double torsion springs you need and their intended use, the shorter your turnaround time will be. Knowing what a spring is going to be used for is valuable information, as it allows the spring manufacturer to advise on spring materials and wire size. It can also aid in determining the style of leg your double torsion springs will have. A straight leg is the most common; however, your application may require a bent leg, offset legs, or looped or hooked ends.

Choosing a Double Torsion Spring Supplier

If you are looking for double torsion springs, there are many factors to consider when choosing a supplier. You need to pick a manufacturer who understands torsion springs and how they are used, with a track record for producing consistent, high-quality springs to a realistic timescale.

Here at Airedale Springs, we’ve been manufacturing an extensive range of springs, including double torsion springs for over 70 years. We work with a range of clients across a number of industries, and we have the expertise to turn your spring requirements into a reality. So if you would like to speak to us about double torsion springs, or any other type of spring we manufacture, contact us today via our online enquiry form.