Fatigue-Resistant Coil Spring

XiaYi Fatigue-Resistant coil spring combines high-strength alloy steel, controlled forming, surface strengthening and precision inspection. The manufacturing process focuses on fatigue durability, stable spring force and accurate installation, making it suitable for vehicles and equipment operating under frequent vibration, changing loads and harsh road conditions.

Fatigue Performance

Material and Durability

High-purity alloy steel with tensile strength of at least 1500 MPa is used to improve resistance to repeated loading. The spring can achieve at least 1.2 million fatigue cycles and 95% elastic retention, while the protective surface treatment provides 500-hour salt spray resistance.

Force Stability

Controlled spring rate and forming accuracy help maintain a more consistent force-stroke response. The stated linearity reaches 98%, supporting predictable suspension behavior during braking, cornering and uneven-road driving.

Dimensional Control

Key Tolerances

Dimensional accuracy affects installation fit, vehicle height and load distribution. XiaYi controls the main dimensions to reduce interference, uneven support and suspension noise.

Batch Consistency

XiaYi uses SPC and CPK monitoring for critical dimensions. CPK values reach ≥1.70 for free length and ≥1.75 for outer diameter, helping maintain consistent performance during mass production and OEM matching.

Product Comparison

The comparison shows that XiaYi focuses on long-cycle fatigue performance, elastic retention and dimensional consistency rather than simply increasing spring strength.

Applications and Cases

Application Scope

XiaYi Fatigue-Resistant coil spring is used in passenger cars, SUVs, EVs, light and heavy commercial vehicles, excavators, loaders and other construction machinery. It is suitable for high-mileage driving, frequent full-load transportation and off-road applications with repeated impact.

EV SUV Case

A mainstream electric SUV experienced elastic attenuation and body sagging after 40,000 km because of high-frequency vibration and heavy battery load. After replacing the original springs with XiaYi fatigue resistant coil springs, the vehicle completed 100,000 km of road testing with elastic retention above 94% and no measurable body sagging. The after-sales failure rate was reduced to less than 1%.

Logistics Fleet Case

A city logistics fleet experienced spring fatigue, brake nose-dive, uneven tire wear and suspension noise under frequent full-load operation. After replacement with XiaYi springs, tire unilateral wear decreased by 35%, while the average suspension maintenance cycle increased by more than 40%.

Loader Case

A 5-ton loader working on gravel and mountain construction sites experienced spring fatigue fractures within 6--8 months. After using XiaYi springs, the service cycle extended to more than 14 months, while operating vibration and rust-related fatigue risks were reduced.

Product Comparison

Selection and Installation

Spring Selection

Spring selection should consider vehicle weight, maximum load, suspension travel, driving conditions and operating frequency. EVs require consideration of battery weight, while commercial vehicles and construction machinery require additional evaluation of full-load and impact conditions.

Custom Parameters

XiaYi supports customized wire diameter, outer diameter, free length, coil pitch, spring rate and load capacity according to drawings, samples and equipment requirements.

Installation Requirements

The spring should be correctly positioned in the upper and lower spring seats and matched with compatible suspension components. After replacement, four-wheel alignment is recommended where applicable. Springs on the same axle should normally be replaced as a pair to maintain balanced suspension support.

Frequently Asked Questions

What applications are suitable for this spring?

XiaYi fatigue resistant coil spring is suitable for passenger cars, SUVs, EVs, commercial vehicles and construction machinery operating under repeated vibration, alternating loads or heavy-duty conditions.

How long can it last?

The product can reach at least 1.2 million fatigue cycles with an elastic retention rate of up to 95%. Actual service life depends on vehicle load, road conditions, operating frequency and installation conditions.

Can the spring be customized?

Yes. XiaYi can customize wire diameter, free length, outer diameter, coil pitch and spring rate according to customer drawings, samples and load requirements.

Brand and Certification

XiaYi specializes in suspension spring development and manufacturing for automotive and mechanical applications. The company has established a quality management system compliant with IATF 16949:2016 and provides customized development, technical matching and batch production for vehicle manufacturers, auto parts distributors and construction machinery customers.