Titanium Ti-6Al-7Nb-STA (Solution treated and aged)
Heat-treated state
UNS R56700 · ASTM F1295 · ISO 5832-11
Choose when maximum strength and fatigue life are needed, e.g. slender hip stems and screws.
Values for the STA condition
Other Ti-6Al-7Nb tempers and conditions
Ti-6Al-7Nb is listed in 7 conditions; see the grade overview at Ti-6Al-7Nb.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Investment cast + HIP (dental/implant castings) | Complex-geometry dental frameworks and prototype implants; coarser lamellar structure, lower ductility than wrought. | 840 | 930 | 8 | 31 HRC | 1.3 % IACS |
ANNDefault Annealed | Standard stocked implant-bar condition: balanced strength, ductility and machinability. | 900 | 1,000 | 13 | 32 HRC | — |
Additive + HIP / vacuum anneal | Post-processed printed parts: pores closed and martensite decomposed, giving wrought-like ductility and fatigue life. | 910 | 1,000 | 13 | 32 HRC | 1.3 % IACS |
As-forged / hot worked + stress relieved | Near-net implant forgings (hip stems, plates) with worked flow lines and slightly higher strength than plain annealed bar. | 940 | 1,030 | 12 | 33 HRC | 1.3 % IACS |
STAThis page Solution treated and aged | Choose when maximum strength and fatigue life are needed, e.g. slender hip stems and screws. | 1,020 | 1,120 | 10 | 36 HRC | 1.3 % IACS |
Additive (L-PBF/EBM) as-built + stress relief | Porous/lattice or patient-specific implants printed from Ti-6Al-7Nb powder; strong but anisotropic with limited ductility. | 1,030 | 1,130 | 8 | 38 HRC | 1.3 % IACS |
Cold drawn | For cerclage wire, K-wires and fine screws where high strength in small sections matters more than ductility. | 1,050 | 1,150 | 9 | 37 HRC | 1.3 % IACS |
What is Ti-6Al-7Nb-STA?
Ti-6Al-7Nb-STA is Ti-6Al-7Nb heat treated to STA — choose when maximum strength and fatigue life are needed, e.g. slender hip stems and screws. Ti-6Al-7Nb-STA has a yield strength of 1,020 MPa (148 ksi) and a tensile strength of 1,120 MPa (162 ksi) — stronger than 94% of titanium grades. Elongation at break is 10% and the elastic modulus is 107 GPa (15.5 Msi). Ti-6Al-7Nb-STA has a density of 4.52 g/cm³ (0.163 lb/in³), heavier than 77% of titanium grades. It melts at 1,600°C (2,912 °F). ANN is the default condition FabDigit quotes; STA is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 80/100, better than 98% of titanium grades
- High strength — 1,020 MPa (148 ksi), better than 94% of titanium grades
Limitations
- Limited ductility — 10%, worse than 93% of titanium grades
- Limited formability — 15/100, worse than 93% of titanium grades
- Difficult to weld — 50/100, worse than 89% of titanium grades
- Low fracture toughness — 58 MPa·√m (52.8 ksi·√in), worse than 87% of titanium grades
Ti-6Al-7Nb-STA properties
Typical room-temperature values for Ti-6Al-7Nb-STA; 22 are specific to this condition. Other listed values are Ti-6Al-7Nb reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
Ti-6Al-7Nb-STA has a density of 4.52 g/cm³ (0.163 lb/in³), heavier than 77% of titanium grades. It melts at 1,600°C (2,912 °F).
Mechanical16
Ti-6Al-7Nb-STA has a yield strength of 1,020 MPa (148 ksi) and a tensile strength of 1,120 MPa (162 ksi) — stronger than 94% of titanium grades. Elongation at break is 10% and the elastic modulus is 107 GPa (15.5 Msi).
Thermal6
Ti-6Al-7Nb-STA is rated for continuous service to 350°C (662 °F). It conducts heat at 7 W/m·K (4.04 BTU/hr·ft·°F), worse than 76% of titanium grades. Thermal expansion is 9 µm/m·K (5 µin/in·°F).
Electrical3
Ti-6Al-7Nb-STA conducts electricity at 1.3 % IACS, worse than 51% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (93/100), better than 72% of titanium grades.
Sustainability4
Producing a kilogram of Ti-6Al-7Nb-STA takes about 700 MJ of energy and emits 45 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 15%.
Manufacturability8
Ti-6Al-7Nb-STA's machinability is poor (15/100, worse than 97% of titanium grades); weldability fair (50/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Ti-6Al-7Nb-STA
Is Ti-6Al-7Nb easy to machine?
Machine like Ti-6Al-4V: rigid setup, sharp uncoated-carbide or PVD tools, low surface speed (25–45 m/min), high feed, flood coolant — poor thermal conductivity causes edge burning and work hardening.
Can Ti-6Al-7Nb be welded?
GTAW, plasma, laser and EBW give sound joints with full argon/vacuum shielding and trailing gas; avoid contamination (O, N, H) which embrittles the weld, and never weld in air or with flux.
Can Ti-6Al-7Nb be formed, bent or molded?
Cold formability is limited (large bend radii, high springback); hot forming/forging at 850–950 °C below the ~1010 °C β-transus is the normal route.
What surface finishes work on Ti-6Al-7Nb?
Takes electropolishing, grit blasting, plasma-sprayed HA and anodizing (colour type II or thick TiO₂) very well; avoid iron contamination during blasting/grinding and passivate per ASTM F86.
Ti-6Al-7Nb 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 |
|---|---|---|
| Alα stabilizer | 5.5 – 6.5 | 6 |
| Nbβ stabilizer, replaces V | 6.5 – 7.5 | 7 |
| Taresidual from Nb feedstock | ≤ 0.5 | 0.25 |
| Fe | ≤ 0.25 | 0.1 |
| O | ≤ 0.2 | 0.15 |
| C | ≤ 0.08 | 0.02 |
| N | ≤ 0.05 | 0.01 |
| H0.009 % bar; higher limits for other forms | ≤ 0.01 | 0 |
| Ti | balance | — |
Ti-6Al-7Nb-STA — frequently asked
What is Ti-6Al-7Nb-STA used for?
Ti-6Al-7Nb-STA is typically used for orthopedic implants, dental implants, bone screws and surgical instruments. In short: vanadium-free implant titanium; ti-6Al-4V strength, F1295 grade; implant-quality bar and forgings.
What is the yield strength of Ti-6Al-7Nb-STA?
Ti-6Al-7Nb-STA has a typical yield strength of 1,020 MPa (148 ksi) and a tensile strength of 1,120 MPa (162 ksi) — stronger than 94% of titanium grades. Strength varies by condition: see the 7 listed tempers.
Is Ti-6Al-7Nb-STA easy to machine?
Not especially — machinability is rated poor (15/100, worse than 97% of titanium grades). Machine like Ti-6Al-4V: rigid setup, sharp uncoated-carbide or PVD tools, low surface speed (25–45 m/min), high feed, flood coolant — poor thermal conductivity causes edge burning and work hardening.
Can Ti-6Al-7Nb-STA be welded?
With care — weldability is rated fair (50/100). GTAW, plasma, laser and EBW give sound joints with full argon/vacuum shielding and trailing gas; avoid contamination (O, N, H) which embrittles the weld, and never weld in air or with flux.
What surface finishes work on Ti-6Al-7Nb-STA?
Takes electropolishing, grit blasting, plasma-sprayed HA and anodizing (colour type II or thick TiO₂) very well; avoid iron contamination during blasting/grinding and passivate per ASTM F86.
Can Ti-6Al-7Nb-STA be formed, bent or molded?
Cold formability is limited (large bend radii, high springback); hot forming/forging at 850–950 °C below the ~1010 °C β-transus is the normal route.
What is the maximum service temperature of Ti-6Al-7Nb-STA?
Ti-6Al-7Nb-STA is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Ti-6Al-7Nb-ANN and Ti-6Al-7Nb-CD?
ANN is the default condition — standard stocked implant-bar condition: balanced strength, ductility and machinability. CD: for cerclage wire, K-wires and fine screws where high strength in small sections matters more than ductility. Yield strength is 900 MPa in ANN versus 1,050 MPa in CD.
Sources
- ASTM F1295 — Wrought Titanium-6Aluminum-7Niobium Alloy for Surgical Implant Applications (UNS R56700) — ASTM International (2023)
- ISO 5832-11 — Implants for surgery, Metallic materials, Part 11: Wrought titanium 6-aluminium 7-niobium alloy — ISO (2014)
- ASM Handbook Vol. 2 / Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- Medical titanium alloy bar datasheets (Ti-6Al-7Nb) — specialty Ti producers (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.