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China Torsion Springs - Reliable Suppliers & Factory for Torque and Twisting Force Solutions
Description
Torsion springs are commonly used in a variety of applications, such as in door hinges, garage doors, levers, and various types of machinery. They are also used in toys, clocks, and other consumer products where a rotating force is required. Sizes range from miniature, used in electronic devices, to large torsion springs used in chair control units. Torsion springs can be made of various materials, including steel, stainless steel, and other alloys, depending on the specific application requirements. They are valued for their ability to provide high torque and for their durability and long lifespan.
A torsion spring is normally close wound but can have a pitch to reduce friction between the coils. Torsion springs resist twisting or rotationally applied force. Depending on the application, a torsion spring can be designed to work in a clockwise or counterclockwise rotation, which will determine the direction of the wind.
Configurations
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Leg Specifications
Leg angle, leg length, and leg style are key considerations for attaching torsion springs in different ways.
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Free Leg Positions
Stock torsion springs offered in 90°, 120°, 180°, 210°, 270°, 300°, and 360° free leg positions with straight legs.
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Double Torsion
Custom double torsion springs feature one right-hand and one left-hand coil set, working in parallel for combined torque output.
There are many options for torsion spring leg configuration so the torsion spring can be attached in different ways. Leg specifications to consider for a torsion spring include leg angle, leg length, and leg style. Springs that are straight or parallel on the same side are considered to have a 0° leg angle and the increasing angle is in the unwinding direction. Common torsion spring designs include straight torsion spring, straight offset torsion spring, hinged torsion spring, short hook end, and hook end designs. Torsion spring ends can be designed with custom bends, twists, hooked or looped end to suit your project needs. SMS Spring stock torsion springs are offered in a choice of 90 degree, 120 degree, 180 degree, 210 degree, 270 degree, 300 degree and 360 degree free leg position with straight legs. Custom double torsion springs consist of one set of coils coiled right hand and one set of coils coiled left hand. These coils are connected, usually with an unwound section between the winds and work in parallel. The sections are designed separately with the total torque being the sum of the two.
Unique Feature
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Energy Storage via Twisting
One of the unique features of a torsion spring is that it can store and release energy through twisting motion, as opposed to the more common compression and extension motion of other types of springs. This twisting motion allows the torsion spring to generate high torque or rotational force, making it well-suited for applications where a rotating force is required, such as in door hinges, garage doors, and various types of machinery.
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Highly Customizable & Durable
Torsion spring properties can be adjusted by varying wire diameter, outer diameter, and number of coils. They are known for high durability and long lifespan, due to their ability to withstand repeated twisting and untwisting without experiencing fatigue failure — a reliable and cost-effective choice for many applications.
Standard Torsion Springs
SMS Spring's have been carefully designed to represent the most commonly used specifications in both inch and metric sizes. Torsion springs are offered in a wide range of options and configurations and are available. Select from thousands of design options, leg angles, and leg lengths, plus left-hand and right-hand wound springs. Torsion springs are offered in a variety of spring materials including music wire, stainless steel 302 and stainless steel 316. SMS Spring music wire springs include plating and stainless steel stock torsion springs, which are ideal for corrosion resistance, include passivation.
Sample Display
SMS Spring offers free plating, expert engineering assistance, live customer support service and much more. SMS Spring stock torsion springs are offered with legs of equal length oriented at varying unloaded angles.
90° Degree Torsion Spring
120° Degree Torsion Spring
180° Degree Torsion Spring
210° Degree Torsion Spring
270° Degree Torsion Spring
300° Degree Torsion Spring
360° Degree Torsion Spring
Custom Torsion Springs
SMS Spring can manufacture custom torsion springs to meet your exact specifications for all your projects. We offer experienced engineering support from design through production. Select from an extensive selection of material and finish options that will be ideal for your torsion spring design application. In addition, we can support your project with CAD assisted torsion spring design, governmental and industrial regulatory expertise, and prototypes through large production runs. SMS Spring offers advanced manufacturing capabilities and a wide variety of options for your torsion spring manufacturing needs such as; advance quality control systems, regulatory expertise including RoHS, REACH and DFARS, CAD assisted product design, in-house prototype production services and global supply chain network. Simply request a quote today or contact a SMS Spring Engineer for design assistance or to answer any questions to help start your custom spring project.
Design Considerations
⚠️ Torsion spring have a number of design elements to consider when working with a torsion spring design. The following is a list of key design considerations when working with torsion springs in your application:
- Torsion spring loads should be specified at a fixed angular position and not at a fixed deflection from the free position.
- Torque spring testing is not easy to perform. Torque measurements for torsion springs can be taken, they may be inconsistent.
- Torsion spring inner diameter reduction and potential binding should be considered in your application.
- For torsion spring applications that require minimum hysteresis (load loss) torsion springs should be designed with space between adjacent coils to reduce frictional losses.
- A torsion spring should always be loaded in a direction that causes its body diameter to decrease. The residual forming stresses are favorable in this direction, but unfavorable when the spring is loaded in a direction that increases body diameter.
- Clearance must be maintained between the mandrel and the torsion spring at all times to prevent binding. The ideal mandrel size is equal to, or slightly less than, 90% of the inside diameter when the spring is fully deflected (minimum diameter). Mandrels significantly smaller than 90% should be avoided to prevent buckling during large deflections.
- Most torsion springs are close wound; therefore, the torsion spring body length will increase when a spring is deflected in the direction that will reduce the coil diameter. In tight housing designs, this increase should be considered.
- Torsion spring direction of wind must always be specified for a torsion spring.
- You can determine direction of wind of a torsion spring by simply holding it in your hand with your fingers placed around the outside of the body and your thumb pointing straight up. If the last coil ends in the same direction that your fingers are pointing, that is the hand (direction of wind) of the spring. The wind of the torsion spring can be right hand, left hand, or double torsion. Good design dictates that torsion springs should be used in the direction that winds the coil.
Common Structures
Torsion springs can be designed and manufactured in wide range of torsion spring end and leg configurations. Special torsion spring leg configurations are available on request. When designing torsion spring ends, it is important to consider that bends, loaded to decrease their radius of curvature, have favorable residual stresses. They can operate at higher applied stress levels than bends that increase the radius by loading. Frequently, torsion spring performance is limited because the sharply bent ends have greater stress than the body.
Axial Torsion Spring Leg Configurations
315 Degree
180 Degree
90 Degree
0 Degree
Tangential Torsion Spring Leg Configurations
315 Degree
180 Degree
90 Degree
0 Degree
Radial Torsion Spring Leg Configurations
315 Degree
180 Degree
90 Degree
0 Degree
Radial Center Over Tangential Torsion Spring
315 Degree
180 Degree
90 Degree
0 Degree
Double Torsion Springs
Special types of torsion springs include double torsion springs and springs having a space between the coils to minimize friction. Double torsion springs consist of one set of coils coiled right hand and one set of coils coiled left hand. These coils are connected, usually with an unwound section between the winds and work in parallel. The sections are designed separately with the total torque being sum of the two.
Terminology
- Active CoilsThe number of coils in the spring that are compressed or extended when it is under load.
- Angular DeflectionThe angle of rotation as measured from the free position to the installed, intermediate or final positions.
- Free AngleThe angle between the arms of a torsion spring when the spring is in the unloaded position.
- Inner DiameterThe inner diameter of the spring, which is the diameter of the circle that the wire makes when the spring is not under any load.
- Leg LengthThe length of the straight sections at each end of the spring, which are used to attach the spring to other components.
- MandrelA rod or shaft over which a torsion spring operates.
- Material TypeThe type of material used to make the spring, which can affect its strength, durability, and other properties.
- Maximum DeflectionThe maximum amount that the spring can be twisted before it reaches its elastic limit and starts to deform permanently.
- Outer DiameterThe outer diameter of the spring, which is the diameter of the circle that the wire makes when it is wound into a spiral.
- RadiusThe bend radius at which a load is applied to a leg. The radius is usually assumed to be equal to ½ the leg length.
- Spring RateThe amount of torque that the spring exerts for a given angle of twist, which is usually measured in units of torque per unit of angle (such as Nm/degree or lb-in/radian).
- TorqueA twisting action in torsion springs which produces rotation, equal to the load multiplied by the distance from the load to the axis of the spring body.
- Total CoilsThe number of coils in the spring when it is under no load.
- Wire DiameterThe diameter of the wire used to make the spring, which is typically specified in inches or millimeters.
Frequently Asked Questions
What is a torsion spring and how does it work?
A torsion spring is a type of mechanical spring that stores and releases energy through twisting or rotational motion. Unlike compression or extension springs, a torsion spring resists rotationally applied force. When torque is applied to the spring, the coils tighten or loosen to generate a restoring force, making it ideal for applications such as door hinges, garage doors, levers, and various types of machinery.
What materials are torsion springs made from?
Torsion springs can be manufactured from a variety of materials depending on the application requirements. Common materials include music wire, stainless steel 302, stainless steel 316, and other alloys. Music wire springs are often available with plating for additional durability, while stainless steel options include passivation for superior corrosion resistance.
What leg configurations are available for torsion springs?
Torsion springs are available in a wide range of leg configurations including axial, tangential, radial, and radial center over tangential styles. Standard free leg positions include 90°, 120°, 180°, 210°, 270°, 300°, and 360°. Custom bends, twists, hooked, or looped ends can also be designed to meet specific project requirements.
What is a double torsion spring?
A double torsion spring consists of one set of coils wound in the right-hand direction and one set wound in the left-hand direction. These two coil sets are connected — usually with an unwound section between them — and work in parallel. Each section is designed separately, and the total torque output equals the sum of both sections combined.
How do I determine the direction of wind for a torsion spring?
To determine the direction of wind, hold the spring in your hand with your fingers placed around the outside of the body and your thumb pointing straight up. If the last coil ends in the same direction that your fingers are pointing, that is the hand (direction of wind) of the spring. Torsion springs can be right-hand wound, left-hand wound, or double torsion, and the direction must always be specified when ordering.
Can torsion springs be customized for specific applications?
Yes, torsion springs are highly customizable. Key design parameters such as wire diameter, outer diameter, number of coils, leg angle, and leg length can all be adjusted to meet the specific requirements of your application. SMS Spring offers CAD-assisted design, in-house prototyping, regulatory expertise (RoHS, REACH, DFARS), and a full range of material and finish options to support custom torsion spring projects of any scale.