Torsion Springs

With over a century of experience, Murphy & Read Spring stands as a global leader in the manufacturing of precision torsion springs, serving the exacting needs of industry-leading companies worldwide. We specialize in precision custom solutions and also offer a wide range of standard stock sizes.

Our readily available stock springs feature straight legs with standard free positions of 90°, 180°, 270°, and 360°, accommodating mandrel sizes from .062” to 1.078”. To ensure proper function and longevity, specifying the correct winding direction (right-hand or left-hand) is essential, and the load should always be applied to close the spring.

If you need a custom solution, Murphy & Read Spring offers comprehensive custom manufacturing capabilities to meet virtually any design requirement. Our dedicated and knowledgeable engineering staff is readily available to provide expert design support. For a wealth of spring-related knowledge, we encourage you to explore the technical resources section of our website.

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What is a Torsion Spring?

Torsion springs are essential mechanical components designed to exert torque or rotational force. They store energy when their legs are rotated about the spring body axis and release it when the rotational force is removed, providing controlled rotational motion or return torques. They are widely used in precision applications ranging from delicate medical instruments and sophisticated electronic assemblies to high-performance aerospace mechanisms and precise valve controls. Other common uses include: hinge mechanisms, lever returns, counterbalance systems, and electrical contact actuation.Torsion Springs

  • Functionality and Applications: Building upon this fundamental definition, torsion springs find critical application in numerous precision engineered products. Their ability to store and release rotational energy makes them indispensable for creating controlled movement, providing return forces, and ensuring the reliable operation of complex mechanisms across diverse industries.
  • Material Selection and Performance: Precision torsion springs can be manufactured from various materials to meet stringent requirements, including stainless steel for biocompatibility and corrosion resistance, high-carbon steel for optimal strength and fatigue life, and specialized alloys like beryllium copper for electrical conductivity and non-magnetic properties. The meticulous choice of material directly impacts the spring’s performance, accuracy of torque delivery, durability under cyclical loading, and operational reliability in demanding environments.

Specific Applications

Precision torsion springs are incredibly versatile components, and their applications span a vast range of industries where accuracy and reliability are paramount. Essentially, torsion springs resist rotational force applied to their legs, storing energy when twisted and releasing it when the force is removed. Murphy & Read Spring specializes in precision, tight tolerance torsion spring applications. Below are examples of how torsion springs are used in some of the sectors we work with frequently:

  • Medical: Used in precision medical devices such as surgical staplers (for controlled deployment), diagnostic tools, and robotic surgery instruments. They provide the accurate and repeatable rotational forces required for critical medical procedures.
  • Hardware: Found in high-quality hardware mechanisms, including precision hinges for optical equipment, calibrated adjustment knobs, and secure latching systems. They ensure smooth, controlled movement and reliable positioning.
  • Automotive: Crucial in sophisticated automotive systems like precise throttle control mechanisms, advanced sensor positioning, and high-performance valve actuators. They contribute to accurate engine management and vehicle control.
  • Household Tools and Appliances: Used in precision tools like calibrated torque wrenches and in high-end appliances requiring controlled rotational movement, such as robotic vacuum cleaner brush drives and specialized food processing equipment. They ensure accurate operation and longevity.
  • Aerospace: Used in critical aerospace applications such as flight control surface actuators, precise instrument positioning mechanisms, and deployment systems for satellites. They must maintain consistent performance under extreme environmental conditions and demanding operational cycles.
  • Valves: Essential in controlling the flow of liquids and gases in sensitive systems, such as analytical instruments and chemical processing equipment. They provide the precise rotational force needed for accurate valve positioning and flow regulation.
  • Computer Peripherals: Used in high-performance input devices like precision trackballs and in mechanisms requiring controlled rotational feedback, ensuring accurate and reliable user interaction.
  • Electric Controls and Assemblies: Found in precision switches, high-reliability relays, and calibrated circuit breakers. They provide the exact rotational force needed for consistent electrical contact and switching operations.
  • Military: Military applications demand the highest levels of reliability and precision, including use in targeting systems, sophisticated communication equipment, and weapon mechanisms requiring accurate rotational control.

Interactive CAD Spring Configurator

Need a CAD drawing? Try our free CAD configurator tool to produce standard or custom spring models.

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Custom Precision Torsion Springs

For applications requiring highly specific performance and dimensional accuracy, Murphy & Read excels in custom precision torsion spring design and manufacturing. Our experienced engineers collaborate closely with you to develop springs that meet your most demanding requirements for:

  • Ultra-Tight Tolerances: Precision control over wire diameter, coil diameter, body length, and leg dimensions.
  • Optimized Leg Configuration: Design and forming of legs to exact angles and lengths for seamless integration.
  • Advanced Material Selection: Utilizing materials best suited for the specific operating environment, including biocompatible and high-performance alloys.
  • Precise Torque Characteristics: Achieving specific torque values at designated deflection angles with minimal variation.
  • Stringent Quality Control: Employing advanced inspection techniques to ensure every spring meets the highest standards.

How to Order Custom Precision Torsion Springs

To discuss your precision torsion spring requirements and receive a detailed quote, please provide us with the following information:

  • Detailed CAD drawings or precise sketches, including all critical dimensions, tolerances (linear and angular), and leg details.
  • Specific material requirements, including grade and any certifications needed.
  • Finish specifications, including surface treatments and any cleanliness requirements.
  • Detailed operating environment information, including temperature range, chemical exposure, and load cycles.
  • Precise torque requirements at specific deflection angles, including allowable tolerances.
  • Quantity requirements for both prototypes and production runs.
Contact Us for Precision Solutions Partner with Murphy & Read for your most demanding precision torsion spring applications. Our engineering expertise and commitment to quality ensure reliable and accurate performance.

Resources

Comprehensive Technical Resources

Our technical resources section is a valuable repository of information on compression spring design, materials, and applications. You’ll find:

  • Spring design calculators and formulas
  • Material selection guides
  • Glossary of spring terminology
  • Application-specific case studies
  • CAD files of common spring types.
  • White papers and articles on advanced spring technologies.

Engineering Support

Our team of experienced spring engineers is available to provide expert design assistance. Whether you need help selecting the right material, calculating spring rates, or optimizing your design for performance and cost-effectiveness, we’re here to help. We offer:

  • Design consultations
  • Prototyping services

Torsion Spring Materials

We use a range of spring materials to meet the needs of our diverse customer base. Here are the materials we use most often and their maximum recommended % tensile:

Material Max recommended% tensile in bending
Music Wire 80%
Chrome Silicon 80%
Chrome Vanadium 80%
302 Stainless Steel 60%
316 Stainless Steel 60%
17-7 Stainless Steel 75%

Torsion Spring Terminology

Abbreviation Meaning
ID Inside Diameter
D Mean Diameter
Dm Minimum Diameter under Deflection
θ Deflection Angle
d Wire Diameter
L Leg Length
Na Number of Active Coils
Nt Number of Total Coils
R Spring Rate
P Applied Force
M Moment or Torque
Sb Bending Stress
c Spring Index
ΔL Deflection
UTS Ultimate Tensile Strength
Torsion Spring Diagram