Multi-wire compression springs

Multi-wire compression springs are made from multiple strands of wire twisted or coiled together to form a single, robust spring element. This design is primarily used when single-wire springs fail due to high impact loads, high frequencies, or dynamic stresses, providing increased force, enhanced damping properties, and greater operational reliability.
Design and Function
The core difference lies in the construction of the "wire" itself, which is a strand of several smaller wires.
Stranded Structure: This structure changes the contact state between the individual wires under load, resulting in increased strength and better material utilization compared to a single solid wire.
Progressive/Non-linear Rate: Under initial low load, the individual wires may contact loosely. As the load increases beyond a critical point, they press tightly together, significantly increasing the spring's stiffness and creating a non-linear load-deflection curve.
High Damping: The internal friction between the individual wire strands provides high damping properties, making them excellent for shock absorption and vibration control applications.
Redundancy: In the event of one wire breaking, the remaining strands can temporarily maintain some functionality, enhancing operational safety and reliability compared to a single-wire spring which would fail completely.
Materials
Multi-wire springs utilize high-quality materials to ensure durability and performance in demanding environments. Common materials include:
High Carbon Steel (e.g., Music Wire): Offers high strength and durability, often used in high-stress applications.
Stainless Steel (e.g., Type 304, 316, 17-7PH): Provides excellent corrosion resistance and good performance across a wide range of temperatures, suitable for medical, aerospace, or marine applications.
Alloy Steels (e.g., Chrome Silicon, Chrome Vanadium): These materials offer superior strength, toughness, and fatigue resistance for heavy-duty applications and high-stress environments.
Common Applications
Multi-wire springs are used in critical and demanding applications where the performance and reliability of single-wire springs are insufficient.
Automotive Industry: Key components in high-performance suspension systems and engine valve systems where they handle high load frequencies and shock impacts.
Aerospace & Defense: Employed in aircraft landing gear systems and other defense equipment that require high fatigue performance and reliability in extreme conditions.
Industrial Machinery: Used in heavy presses, vibration isolation equipment, and high-impact machinery where their damping properties and load capacity are essential for safety and performance.
Medical Devices: Found in critical medical equipment requiring high precision and reliability, such as respiratory machines and surgical instruments.
Power Generation: Used in valves, engines, and turbines to absorb pressure surges and maintain consistent forces in high-stress environments.