Nickel Alloy Nitinol
GB Nitinol · ASTM F2063
Nitinol is a near-equiatomic nickel-titanium alloy covered by ASTM F2063, whose reversible martensitic transformation produces shape-memory and superelastic behaviour.
Values for the O condition
Nitinol tempers and conditions
Nitinol is supplied in 7 conditions, soft to hard. O is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Shape Memory | Use the martensitic state (Af ≈ 45–95 °C) when the part is deformed softly at room temperature and recovers its shape on heating, as in thermal actuators, couplings and thermal switches. | 130 | 1,000 | 30 | 210 HV | 9 W/m·K |
ODefault Annealed | Fully annealed at 700–850 °C, this general-purpose stock state offers the best ductility for further machining, forming and subsequent shape setting; room-temperature phase depends on composition. | 400 | 950 | 30 | 22 HRC | — |
Straight Annealed wire | Order straight-annealed wire when coil stock must come off the spool already straight for guidewires or spring winding, eliminating a secondary straightening operation. | 450 | 1,250 | 12 | 30 HRC | 2.1 % IACS |
Superelastic (austenitic, Af ≈ 0…18 °C), shape-set + aged | Pick the shape-set and aged austenitic state (Af ≈ 0–18 °C) for stents, guidewires and archwires needing 6–8% recoverable strain at room temperature; service is limited to 90 °C. | 480 | 1,400 | 13 | 32 HRC | 18 W/m·K |
constrained heat set 450–550 °C then quenched | Constrain the part in a fixture, heat set at 450–550 °C and quench to fix the memorized shape and transformation temperature; this is the final functional state of a finished part. | 500 | 1,300 | 12 | 33 HRC | 2 % IACS |
Nitinol 60 | Choose the 60 wt% Ni variant, solution treated and hardened to HRC 55–62, for corrosion-resistant, non-magnetic bearings and cutting tools; it has no usable shape-memory function and only 3% elongation. | 1,100 | 3 | 58 HRC | — | |
30–50 % cold reduction, as-drawn (no final anneal) | Choose 30–50% cold-drawn material with no final anneal for maximum strength and stiffness, 1300 MPa yield, in high-strength wire and spring blanks where memory or superelasticity is not needed. | 1,300 | 1,600 | 6 | 38 HRC | 1.6 % IACS |
What is Nitinol?
Nitinol is a near-equiatomic nickel-titanium alloy covered by ASTM F2063, whose reversible martensitic transformation produces shape-memory and superelastic behaviour. It is stocked in superelastic (SE), shape-memory (SM), shape-set, annealed, cold-worked and 60NiTi conditions, usually as fine wire, tube, thin sheet and small machined components for self-expanding medical devices and constant-force elements. The trade-offs are severe: machinability score 12, heavy work hardening, a 300 °C service limit, and brittle intermetallics if welded directly to steel; where elastic recovery is not required, 316LVM or MP35N is simpler and cheaper. Nitinol has a density of 6.45 g/cm³ (0.233 lb/in³), lighter than 99% of nickel alloy grades. It melts at 1,300°C (2,372 °F). Nitinol has a yield strength of 400 MPa (58 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 56% of nickel alloy grades. Elongation at break is 30% and the elastic modulus is 75 GPa (10.9 Msi).
What is Nitinol used for?
- Cardiovascular stents
- Guidewires and catheter components
- Orthodontic archwires
- Eyeglass frames
- Bone staples and compression implants
- Thermal actuators and switches
- Shape-memory pipe couplings and fasteners
Advantages
- Lightweight — 6.45 g/cm³ (0.233 lb/in³), better than 99% of nickel alloy grades
- Conducts heat well — 18 W/m·K (10.4 BTU/hr·ft·°F), better than 85% of nickel alloy grades
- High electrical conductivity — 1.7 % IACS, better than 76% of nickel alloy grades
Limitations
- Low stiffness — 75 GPa (10.9 Msi), worse than 100% of nickel alloy grades
- High embodied carbon — 26 kg CO₂/kg, worse than 100% of nickel alloy grades
- Limited service temperature — 300°C (572 °F), worse than 99% of nickel alloy grades
- Low fracture toughness — 40 MPa·√m (36.4 ksi·√in), worse than 95% of nickel alloy grades
- Difficult to weld — 35/100, worse than 76% of nickel alloy grades
Nitinol properties
Typical room-temperature values for Nitinol-O; bars are the position among nickel alloy grades.
Physical3
Nitinol has a density of 6.45 g/cm³ (0.233 lb/in³), lighter than 99% of nickel alloy grades. It melts at 1,300°C (2,372 °F).
Mechanical11
Nitinol has a yield strength of 400 MPa (58 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 56% of nickel alloy grades. Elongation at break is 30% and the elastic modulus is 75 GPa (10.9 Msi).
Thermal5
Nitinol is rated for continuous service to 300°C (572 °F). It conducts heat at 18 W/m·K (10.4 BTU/hr·ft·°F), better than 85% of nickel alloy grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).
Electrical3
Nitinol conducts electricity at 1.7 % IACS, better than 76% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 67% of nickel alloy grades.
Sustainability4
Producing a kilogram of Nitinol takes about 400 MJ of energy and emits 26 kg of CO₂ — more than 100% of nickel alloy grades. Typical recycled content is 5%.
Manufacturability8
Nitinol's machinability is not recommended (12/100, worse than 86% of nickel alloy grades); weldability fair (35/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the nickel alloy family
Yield strength against density for every nickel alloy grade FabDigit runs. Nitinol is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Nitinol
Is Nitinol easy to machine?
Extremely difficult to cut because of rapid work hardening and low thermal conductivity; prefer wire EDM, sinker EDM, laser tube cutting and grinding. When turning or milling is unavoidable, use sharp coated carbide, low speed with heavy feed and abundant coolant.
Can Nitinol be welded?
Laser, resistance and inert-gas-shielded TIG welding of Nitinol to itself is feasible and retains part of the superelastic response. Direct welding to stainless steel or other dissimilar metals forms brittle intermetallic compounds — use a transition layer or mechanical/crimped joints instead.
Can Nitinol be formed, bent or molded?
Cold formability is good in the annealed martensitic condition, but springback is large. Set the final shape by constraining the part in a fixture at 450–550 °C for several minutes followed by a water quench; apply an intermediate anneal after 30–40% cold work.
Manufacturability
The process limits FabDigit's quote engine applies to Nitinol. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Poor12 / 100 |
|---|---|
| ISO material group | S.1 |
| Cutting speed (rough / finish) | 40 / 55 m/min |
| Minimum wall | 1.5 mm |
| Minimum internal radius | 2 mm |
| Drill depth limit | 3× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair45 / 100 |
|---|---|
| Weldability | Poor35 / 100 |
Nitinol chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| NiASTM F2063; ±0.1% Ni shifts transformation temp ~10 °C | 54.5 – 57 | 55.8 |
| C | ≤ 0.05 | |
| Oas oxygen equivalent | ≤ 0.05 | |
| H | ≤ 0.01 | |
| Ncontrolled with O as oxygen equivalent | ≤ 0.05 | |
| Fe | ≤ 0.05 | |
| Cr | ≤ 0.01 | |
| Cu | ≤ 0.01 | |
| Co | ≤ 0.05 | |
| Nb | ≤ 0.03 | |
| Ti | balance |
What surface finishes work on Nitinol?
Chemical etching to remove black oxide followed by electropolishing produces a titanium-rich passive layer that reduces nickel release. Nitric acid passivation per ASTM F86 or colour anodizing for identification are options; avoid fluoride-bearing pickling solutions.
Surface treatments FabDigit runs on nickel alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Equivalent designations
Standards and trade names that resolve to Nickel Alloy Nitinol in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- F2063
- Also called
- NiTi
How much does Nitinol cost?
Nitinol is a premium-cost nickel alloy ($$$), pricier than about 57% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Nitinol — frequently asked
What is Nitinol used for?
Nitinol is typically used for cardiovascular stents, guidewires and catheter components, orthodontic archwires, eyeglass frames, bone staples and compression implants and thermal actuators and switches. In short: shape memory medical wire.
What is the yield strength of Nitinol?
Nitinol has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 56% of nickel alloy grades. Strength varies by condition: see the 7 listed tempers.
Is Nitinol easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 86% of nickel alloy grades). Extremely difficult to cut because of rapid work hardening and low thermal conductivity; prefer wire EDM, sinker EDM, laser tube cutting and grinding. When turning or milling is unavoidable, use sharp coated carbide, low speed with heavy feed and abundant coolant.
Can Nitinol be welded?
With care — weldability is rated fair (35/100). Laser, resistance and inert-gas-shielded TIG welding of Nitinol to itself is feasible and retains part of the superelastic response. Direct welding to stainless steel or other dissimilar metals forms brittle intermetallic compounds — use a transition layer or mechanical/crimped joints instead.
What surface finishes work on Nitinol?
Chemical etching to remove black oxide followed by electropolishing produces a titanium-rich passive layer that reduces nickel release. Nitric acid passivation per ASTM F86 or colour anodizing for identification are options; avoid fluoride-bearing pickling solutions.
Can Nitinol be formed, bent or molded?
Cold formability is good in the annealed martensitic condition, but springback is large. Set the final shape by constraining the part in a fixture at 450–550 °C for several minutes followed by a water quench; apply an intermediate anneal after 30–40% cold work.
What is the maximum service temperature of Nitinol?
Nitinol is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Nitinol-O and Nitinol-SM?
O is the default condition — fully annealed at 700–850 °C, this general-purpose stock state offers the best ductility for further machining, forming and subsequent shape setting; room-temperature phase depends on composition. SM: use the martensitic state (Af ≈ 45–95 °C) when the part is deformed softly at room temperature and recovers its shape on heating, as in thermal actuators, couplings and thermal switches. Yield strength is 400 MPa in O versus 130 MPa in SM.
How much does Nitinol cost?
Nitinol is a premium-cost nickel alloy ($$$), pricier than about 57% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in Nitinol?
Yes — Nitinol is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM F2063 — Wrought Nickel-Titanium Shape Memory Alloys for Medical Devices — ASTM (2018)
- ASTM F2005 — Terminology for Nickel-Titanium Shape Memory Alloys — ASTM (2015)
- ASTM F2516 — Tension Testing of Nickel-Titanium Superelastic Materials — ASTM (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- Nitinol physical & mechanical property datasheets — Memry / SAES Smart Materials / Johnson Matthey Medical (2023)
- 60NiTi bearing alloy property reports — NASA Glenn Research Center (2014)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.