Nitinol Spring — Superelastic & Shape Memory Alloy ASTM F2063 Supplier
Princeton Nitinol supplies custom Nitinol (NiTi) springs engineered for superelastic and shape memory performance. Fully compliant with ASTM F2063, ASTM F2633, and ISO 9001:2015. Wire diameter from 0.05 mm, custom coil dimensions, free lengths, and spring rates. Af temperatures from −50 °C to +350 °C — trusted by medical device OEMs, aerospace engineers, and industrial actuator manufacturers worldwide.
ASTM F2063 Certified Springs
Medical-grade chemistry and transformation temperature control for implantable device springs, orthodontic coil springs, and surgical instrument components.
Af from -50 °C to +350 °C
Precision heat treatment to dial in your exact activation temperature. ±2 °C accuracy for shape memory springs. Verified by DSC per ASTM F2004.
Six Spring Configurations Available
Compression, tension, torsion, open coil, closed coil — in superelastic and shape memory variants. Custom wire diameter from 0.05 mm.
Product Overview — Custom NiTi Springs
Our superelastic Nitinol springs provide constant force over large deflections — a capability unmatched by steel springs. Where a steel spring follows Hooke’s law (force proportional to displacement), a superelastic Nitinol spring exhibits a stress plateau that delivers near-constant force across its working range. This makes them ideal for orthodontic coil springs, constant-force actuators, compliant robotic joints, and vibration isolation mounts.
Shape memory Nitinol springs function as solid-state thermal actuators. Compressed or stretched when cold (martensitic phase), they recover their preset coil geometry when heated above Af — generating up to 600 MPa recovery stress. This enables motorless, gearless actuation for applications from aerospace deployable structures and HVAC fire dampers to automotive thermal valves and consumer safety devices. Every spring is fully traceable to its wire heat lot with full material certification.
Key Features & Benefits
| Feature | Benefit |
|---|---|
| Superelastic Constant-Force Plateau | Near-constant force over large deflections — unlike steel springs that follow Hooke’s law. Ideal for orthodontic coil springs and constant-force actuators. |
| Shape Memory Actuation — up to 600 MPa Recovery Stress | Solid-state thermal actuator — generates significant force without motors, gears, or hydraulics. >98% shape recovery in single-cycle tests. |
| ASTM F2063 / ASTM F2633 Compliant | Meets strict chemical, mechanical, and biocompatibility requirements for medical implant and surgical instrument springs. |
| Temperature Control Accuracy ±2 °C | Precision Af targeting for applications requiring exact actuation temperature — fire dampers, thermal switches, engine controls. |
| Wide Af Range — -50 °C to +350 °C | From cryogenic actuators to high-temperature industrial triggers. NiTiHf high-temperature grades available for applications above 100 °C. |
| Custom Spring Geometry | Wire diameter, coil diameter, free length, number of active coils, and end configuration — all customized to your force-deflection requirements. |
| Biocompatible — TiO2 Passive Layer | Natural titanium oxide surface resists corrosion; nickel release well below ISO 10993 thresholds. Suitable for long-term implantable springs. |
| Spring Rate & Force Verification | Every production lot tested for spring rate, free length, and force at specified deflection. Full test data included with material certification. |
Technical Specifications
Spring Types & Configurations
| Spring Type | Superelastic Variant | Shape Memory Variant |
|---|---|---|
| Compression Spring | Constant-force compression, open or closed coil | One-way (stretched cold, contracts when heated) or two-way (auto-expands cold, contracts hot) |
| Tension Spring | Constant-force extension, with or without hooks | One-way (compressed cold, extends when heated) or two-way (auto-contracts cold, extends hot) |
| Torsion Spring | Superelastic angular deflection recovery | Shape memory angular actuation — twists back to preset angle when heated |
| Open Coil Spring | Gaps between coils — constant force over full compression range | Gaps close when activated — used in orthodontic space closure |
| Closed Coil Spring | Coils touch at rest — high initial force, superelastic deflection | Coils separate when activated — expansion actuator |
Physical & Mechanical Properties
| Property | Specification |
|---|---|
| Material | Nickel-Titanium (NiTi) Alloy — near-equiatomic |
| Nickel Content (Nominal) | 54.5 – 57.0 wt% (balance titanium) |
| Wire Diameter | 0.05 mm and up (custom) |
| Tensile Strength (Superelastic) | ≥ 850 – 900 MPa |
| Max Recovery Stress | 600 MPa |
| Shape Memory Recovery | > 98% (single-cycle) |
| Af Temperature Range (Binary NiTi) | −50 °C to +100 °C |
| Af Temperature Range (NiTiHf — High Temp) | +90 °C to +350 °C |
| Af Temperature Accuracy | ±2 °C (shape memory springs) |
| Density | ~6.45 g/cm³ |
| Melting Point | ~1310 °C |
| Standards | ASTM F2063, ASTM F2633, ISO 5832-11 |
Surface Finish Options
Applications
Medical Devices
- Orthodontic coil springs (50–300 g force)
- Self-expanding stent springs
- Surgical instrument return springs
- Implantable actuator springs
- Orthopaedic staple compression springs
- Endoscopic tool flexures
- Drug delivery pump actuators
- Dental implant abutment springs
Aerospace & Defense
- Satellite antenna deployment springs
- Solar array release actuators
- Cryogenic valve springs
- Vibration isolation mounts
- Thermal switch triggers
- Reconfigurable rotor blade springs
- Payload release mechanisms
Industrial & Consumer
- HVAC fire damper springs
- Automotive thermostat springs
- Robotic joint actuators
- Eyeglass frame flexures
- Watch/timer actuator springs
- Coffee machine thermal valves
- Fire safety sprinkler triggers
Why Choose Princeton Nitinol
VIM + VAR Melted Wire Stock
All springs wound from double-melt wire — minimizes inclusions that become fatigue initiation sites in cyclic spring applications.
Full Documentation Package
Certificate of conformance, DSC thermogram (ASTM F2004), wire tensile report, spring rate test data, and dimensional inspection with every shipment.
Precision Af Control ±2 °C
DSC-verified transformation temperature targeting. Critical for shape memory springs where actuation temperature determines device function.
Custom Spring Design Support
Engineering team available to calculate spring geometry from your force-deflection-temperature requirements. Send us your spec — we’ll return a design.
Prototyping & Small-Batch Production
Low MOQ for R&D and design verification. Manual cold forming for shape memory prototypes; machine winding for superelastic production.
Global Shipping & Export Packaging
Springs packed in custom compartment trays to prevent coil entanglement. Moisture-barrier packaging. DAP/FCA incoterms worldwide.
Packaging & Available Forms
| Form | Description | Typical Packaging |
|---|---|---|
| Compression Springs | Open or closed coil, superelastic or shape memory | Bulk-packed or individually compartmented trays |
| Tension Springs | With or without hook ends, superelastic or shape memory | Individually sleeved to prevent tangling, compartment trays |
| Torsion Springs | Custom leg configuration, superelastic or shape memory | Custom compartment trays per spring geometry |
| Custom Spring Assemblies | Spring + mating component sub-assembly | Per customer specification — fully assembled and tested |
Frequently Asked Questions
A Nitinol spring is a coiled nickel-titanium (NiTi) shape memory alloy component available in two functional types: superelastic springs (exhibit large recoverable deformation at room temperature without heating) and shape memory springs (actuated by temperature change — returns to a preset shape when heated above Af). Spring types include compression, tension, and torsion configurations, with wire diameters from 0.05 mm. Conforms to ASTM F2063.
ASTM F2063 is the international standard for wrought nickel-titanium shape memory alloys for medical devices and surgical implants. For springs, it governs chemical composition, transformation temperature methodology, and mechanical properties. Medical-grade springs used in implantable devices and surgical instruments require ASTM F2063 compliance for FDA and EU MDR regulatory submissions.
Superelastic (austenitic) springs are used above their Af temperature — they provide constant force over large deflections at room temperature, ideal for orthodontic coil springs, constant-force actuators, and compliant mechanisms. Shape memory springs are deformed cold and recover their preset coil geometry when heated above Af, suitable for thermal actuators, fire safety triggers, HVAC dampers, and temperature-controlled valves. Af can be tuned from -50 C to +350 C.
We manufacture compression springs, tension springs (with or without hooks), torsion springs, open coil springs, and closed coil springs. Wire diameter from 0.05 mm. Custom coil diameters, free lengths, number of coils, and spring rates. Shape memory recovery >98% in single-cycle tests. Tensile strength >=850-900 MPa (superelastic). Temperature control accuracy: +/-2 C for shape memory springs. All dimensions and specifications customized to your application.
We supply bright/polished, light oxide (golden to brown), black oxide, and electropolished spring surface finishes. Light oxide finish is the most common for shape memory springs. Electropolished finish is recommended for medical applications where surface smoothness and reduced nickel release are critical. Custom surface treatments available on request.
Standard MOQ is 500 pieces or 1 kg, whichever is less. Smaller R&D and prototyping quantities are available. Stock spring designs ship in 5–7 business days. Custom spring designs with specified dimensions and Af temperature delivered in 2–4 weeks. Volume pricing applies at 1000, 5000, and 10000+ piece tiers. Contact us with your spring specifications for a detailed quotation.
Also available: Nitinol Alloy Wire ASTM F2063 | Nitinol Sheet & Plate ASTM F2063 | Nitinol Bar & Rod | Nitinol Tube | Shape Memory Flat Wire