Why do canted coil springs lose contact force over time? Explore the key causes such as stress relaxation, material creep, temperature effects, and groove design errors—plus proven solutions to maintain long-term spring performance.
Пружины со скошенными витками are widely used in high-reliability applications such as electrical contacts, EMI/RFI shielding, precision seals, valves, and medical devices. Their unique angled coil geometry allows them to deliver consistent force over a wide deflection range—an advantage over traditional compression or wave springs.
However, despite their superior design, canted coil springs can still experience contact force loss over time if they are not properly specified, manufactured, or installed. This gradual reduction in force can lead to electrical intermittency, sealing failure, increased contact resistance, or system downtime.
Understanding why contact force loss occurs is essential for engineers, designers, and procurement teams aiming to maximize product reliability and service life. This article explores the primary mechanisms behind force degradation and outlines practical strategies to prevent it.
Contact force refers to the continuous mechanical pressure exerted by a spring against a mating surface—such as a conductive housing, shaft, or sealing groove. In canted coil springs, this force is generated by the elastic deformation of angled coils under compression or radial deflection.
Unlike traditional springs, canted coil springs:
Yet, contact force is not immune to long-term degradation.
Stress relaxation is the most common cause of force loss.
When a spring is held at a constant deflection for an extended period, internal stresses gradually redistribute within the material. Even without visible deformation, the spring’s output force decreases.
Key contributors:
Stress relaxation is especially critical in static sealing and electrical contact applications.
Creep occurs when a material slowly deforms under constant load, particularly at elevated temperatures.
Materials with lower creep resistance—such as standard stainless steel—may experience permanent deformation over time, resulting in reduced spring force.
High-risk environments include:
Temperature accelerates both stress relaxation and creep.
As operating temperature increases:
If a spring material is used near or beyond its temperature limit, force loss can occur much faster than expected.
Canted coil springs are designed to operate within a specific deflection range. Exceeding this range can cause:
Once the elastic limit is exceeded, the spring cannot fully recover its original force.
Improper groove geometry is a hidden but critical cause of force loss.
Common groove design errors include:
These issues can cause uneven loading, localized stress concentration, and accelerated fatigue.
In dynamic applications, repeated loading and unloading cycles can gradually reduce force due to:
While canted coil springs excel in cyclic environments, material choice and surface treatment remain critical.
| Cause | Primary Risk Factor | Typical Impact |
|---|---|---|
| Stress relaxation | Time + temperature | Gradual force decay |
| Material creep | High load, high heat | Permanent deformation |
| Over-compression | Poor sizing | Immediate force loss |
| Groove misdesign | Installation error | Uneven load distribution |
| Fatigue wear | High cycle count | Long-term degradation |
High-performance alloys significantly reduce force loss:
| Материал | Key Advantage |
|---|---|
| Elgiloy® | Excellent fatigue & relaxation resistance |
| MP35N | High strength, corrosion resistance |
| Инконель® | Superior high-temperature stability |
| Бериллиевая медь | Ideal for electrical conductivity |
| Хастеллой® | Extreme chemical environments |
Proper control of:
ensures balanced stress distribution and long-term force stability.
Always select materials and designs rated above actual operating temperatures to create a safety margin against relaxation and creep.
Precision-machined grooves with smooth finishes and correct tolerances dramatically extend spring life.
Advanced forming processes and controlled heat treatment improve:
| Design Strategy | Benefit |
|---|---|
| High-grade alloy | Reduced creep & relaxation |
| Optimized deflection | Prevents plastic deformation |
| Precision groove | Even force distribution |
| Custom load tuning | Application-specific reliability |
Canted Coil Springs Engineered to Prevent Contact Force Loss
HANDA canted coil springs are designed to deliver long-term, stable contact force in demanding sealing, electrical contact, and EMI shielding applications. Unlike conventional springs that suffer rapid stress relaxation, HANDA’s precision-engineered angled coil design evenly distributes load across the entire spring, minimizing localized stress and force decay over time.
Manufactured from premium materials such as stainless steel, Elgiloy®, MP35N, Inconel®, Hastelloy®, and beryllium copper, our canted coil springs offer exceptional resistance to creep, fatigue, corrosion, and elevated temperatures. Advanced heat treatment and tight dimensional control further enhance elastic recovery and long-term performance.
HANDA springs maintain consistent force across wide deflection ranges, making them ideal for both static and dynamic environments. Applications include aerospace systems, medical devices, semiconductor equipment, valves, connectors, and EMI/RFI shielding assemblies.
Custom spring sizes, load profiles, and material options are available to meet exact application requirements. By choosing HANDA canted coil springs, engineers can effectively prevent contact force loss, improve system reliability, and extend product service life.
Canted coil springs do not lose contact force randomly—force degradation is the result of identifiable mechanical, thermal, and design-related factors. By understanding stress relaxation, material creep, temperature effects, and groove design principles, engineers can make informed decisions that significantly extend spring life.
With proper material selection, optimized geometry, and precision manufacturing, canted coil springs can maintain reliable contact force for millions of cycles—even in the most demanding environments.