Aerospace Waved Springs: Precision Elastic Components by SUNZO (Jiangsu Sunzo)

The aerospace industry depends on elastic components that perform consistently in demanding operating environments — where wide temperature swings, corrosion, vibration, and dynamic loads challenge every part of an assembly. SUNZO (Jiangsu Sunzo Spring Elastic Technology Co., Ltd.), an elastic-component manufacturer headquartered in Suqian, Jiangsu Province, China, designs and produces aerospace-grade waved springs (wave springs) for mission-critical systems in commercial aviation, defense platforms, and satellite programs.

A waved spring is a compact elastic element formed from a metal ring with precisely shaped peaks and valleys along its circumference. When compressed axially, the wave profile deflects and generates a predictable load within a small installation space. Compared with conventional coil springs, a waved spring delivers comparable load capacity in roughly half the axial height, making it well suited to applications where envelope space is limited — such as avionics housings, actuator assemblies, and bearing preload systems.

Waved springs are available in two common forms: single-layer closed designs, where the ring is formed from one strip with joined ends, and multi-layer designs, which stack several thin layers to distribute load and improve damping. SUNZO manufactures both types, along with tapered and application-specific profiles.

• Compact size: A waved spring occupies roughly half the axial space of a coil spring delivering the same load, freeing envelope space for other components.
• Predictable load-deflection behavior: The formed wave profile produces a stable, repeatable force curve, supporting precise preload control in assemblies such as bearing stacks and valve actuators.
• Weight reduction: Material volume is lower than that of an equivalent coil spring, contributing to weight savings that matter in airframe and spacecraft design.
• Design flexibility: Wave profiles can be integrated into thin-walled housings and compact mechanisms where coil springs are difficult to fit.

In aerospace programs, elastic components must satisfy requirements that go beyond general industrial specifications. Traceability is fundamental: material lots, heat treatment records, and inspection results must be traceable from raw material to finished part. Qualification evidence is another pillar — design validation typically requires documented load-deflection curves, thermal cycling results, and fatigue data. Production lots must reproduce validated performance within tight tolerances, since flight-critical assemblies are not re-qualified part by part. Components may also face temperature extremes, vacuum, radiation, and aggressive media across a single service life.

Waved springs address these requirements through their simple geometry, which leaves fewer failure modes than multi-part assemblies; repeatable CNC forming; and the availability of aerospace-grade alloys with documented mechanical properties. These characteristics make waved springs a practical choice when a compact, predictable axial spring element is required in flight hardware.

SUNZO waved springs are produced from materials with tensile strength up to 1,400 MPa (Inconel 718), and validated designs withstand dynamic impact loads of 500G. This combination preserves structural integrity during sudden load spikes — for example, landing gear deployment, retraction shocks, and engine start-up transients. The predictable deflection range also allows designers to keep operating loads within the elastic region across the full service envelope.

Engineered for service from -270°C (cryogenic satellite environments) to 650°C (jet engine turbine sections), SUNZO waved springs maintain stiffness and load capacity with minimal drift across the temperature envelope. Nickel-based superalloys with low thermal expansion coefficients keep the wave geometry stable through repeated thermal cycling, reducing the risk of preload relaxation in bolted joints and bearing systems.

CNC-formed profiles hold a dimensional tolerance of +/-0.02 mm, enabling consistent axial preload from 5 N to 500 N and deformation under load of 0.03 mm or less in compact assemblies such as avionics housings and actuator systems. Repeatable geometry translates into predictable force-deflection behavior from part to part and lot to lot, simplifying assembly qualification and reducing inspection effort.

Material selection determines long-term reliability in aerospace service. SUNZO offers superalloys and high-grade stainless steels matched to specific operating conditions, with material certificates and traceability supporting quality programs.

Inconel 718 is a nickel-chromium superalloy with high creep resistance at 650°C, making it a common choice for turbine engine components and exhaust systems. Its low thermal expansion coefficient keeps dimensions stable through thermal cycling, reducing the risk of preload loss in bolted joints. For waved springs exposed to engine heat or repeated start-stop cycles, Inconel 718 balances high-temperature strength with formability during manufacturing.

Inconel X-750 provides high fatigue strength for cyclic load applications such as flap actuators and fuel control mechanisms. In wave spring form, it sustains 10⁷+ load cycles without measurable performance degradation, making it a reliable option for components that experience continuous vibration and repeated actuation.

SUS316 is a marine-grade stainless steel containing 2-3% molybdenum, providing enhanced corrosion resistance for coastal and high-humidity environments such as helicopter rotor systems. SUNZO SUS316 waved springs pass 1,000+ hours of salt spray testing per ASTM B117, supporting applications where long-term corrosion performance is required.

Surface treatments extend service life when waved springs operate in aggressive conditions — salt spray, humidity, fuel exposure, or wear environments.

Dacromet is a chromate-free zinc-aluminum flake treatment that provides 1,000+ hours of salt spray resistance. In comparative testing, Dacromet-coated parts provide roughly three times the salt-spray protection of conventional zinc plating, making the coating a practical choice for coastal and high-moisture applications where corrosion protection must be maintained over long maintenance intervals.

Phosphating improves lubricity and wear resistance for moving parts such as landing gear hinges. The phosphate layer reduces friction by about 28% compared with untreated surfaces, lowering wear rates and easing initial break-in of sliding interfaces.

SUNZO provides end-to-end engineering support for aerospace programs:

• Tailored design: From standard single-layer closed waved springs (8 mm–500 mm diameter) to multi-layer and tapered profiles, load-deflection characteristics are optimized through FEA simulation (ANSYS) before prototyping.
• Stringent testing: Manufacturing follows AS9100D and NADCAP quality frameworks, with verification including ultrasonic flaw detection, thermal cycling from -270°C to 650°C, and load testing within +/-2% force tolerance.
• Standards-based product lines: In addition to custom waved springs, SUNZO produces Belleville disc springs per DIN 2093, disc spring washers per DIN 6796, and related elastic elements, supported by in-house R&D, production, and technical service.

SUNZO maintains a quality management system aligned with aerospace expectations. Incoming material control verifies raw material certificates against alloy specifications before production. Process documentation records forming, heat treatment, and finishing parameters for each production lot. Inspection coverage — dimensional inspection, ultrasonic flaw detection, and load testing — is applied according to the agreed inspection level. Internal audits and feedback loops support ongoing refinement of tooling and process parameters.

For aerospace orders, SUNZO can provide a documentation package covering material certificates, inspection reports, and conformity statements aligned with project requirements, supporting downstream review and acceptance.

To obtain a suitable design, provide the following parameters to the SUNZO engineering team:

• Installation envelope: inner diameter, outer diameter, and available axial height.
• Load requirements: required preload in newtons at a defined deflection, or a full load-deflection curve.
• Operating conditions: temperature range, media exposure, vibration level, and expected number of cycles.
• Material and surface treatment preferences, or ask SUNZO to recommend based on the operating environment.
• Qualification requirements: applicable standards, documentation, and lot traceability.

SUNZO waved springs are applied across critical systems:

• Landing gear assemblies: maintain bearing preload and absorb shock during touchdown and taxi, where impact loads are sudden and repeated.
• Engine control systems: ensure precise valve actuation under high-temperature conditions, where consistent load is required across thermal cycles.
• Satellite mechanisms: provide stable tension in solar panel deployment and antenna positioning systems, operating reliably in cryogenic vacuum environments.
• Avionics and actuators: support compact assemblies where axial space is limited and preload must be controlled within tight tolerances.

SUNZO is the brand of Jiangsu Sunzo Spring Elastic Technology Co., Ltd., a specialized manufacturer headquartered in Suqian, Jiangsu Province, China. The company focuses on the research, development, production, sales, and technical service of elastic elements — including waved springs, disc springs, and Belleville washers. As a mixed-ownership enterprise, SUNZO combines industrial manufacturing experience with an in-house engineering team, serving customers in aerospace, energy, automotive, and general industry with both standard parts and custom-engineered solutions.

Whether for commercial aviation or space exploration, SUNZO aerospace waved springs combine material science, precision engineering, and rigorous quality control to deliver dependable performance in demanding environments. For design support, material selection guidance, or a quotation, contact the SUNZO engineering team.