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Titanium Ti-6Al-2Sn-4Zr-6Mo Annealed

Temper

UNS R56260

Lower-strength, more ductile and dimensionally stable condition for stock that will be re-heat-treated or for less critical parts.

High cost $$$$

Values for the Annealed condition

Other Ti-6Al-2Sn-4Zr-6Mo tempers and conditions

Ti-6Al-2Sn-4Zr-6Mo is listed in 5 conditions; see the grade overview at Ti-6Al-2Sn-4Zr-6Mo.

Compare all 5 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Solution annealed
Intermediate softer condition used for machining or hot working before the final aging cycle.9009701532 HRC0.9 % IACS
AnnealedThis page
mill/duplex annealed
Lower-strength, more ductile and dimensionally stable condition for stock that will be re-heat-treated or for less critical parts.9501,0301334 HRC—
Beta-STA
Pick when fracture toughness, creep and crack-growth resistance matter more than tensile ductility (heavier disks and thick forgings).1,0101,100837 HRC1 % IACS
Solution treated and overaged
Overaged cycle trading ~5–10 % tensile strength for better thermal stability, toughness and creep life in long-duty engine hardware.1,0201,1001236 HRC1 % IACS
STADefault
Solution treated and aged
Standard supply condition for bar, billet and forgings: highest strength for compressor disks, blades and high-load fittings up to ~400 °C.1,1001,1701038 HRC—

What is Ti-6Al-2Sn-4Zr-6Mo Annealed?

Ti-6Al-2Sn-4Zr-6Mo Annealed is Ti-6Al-2Sn-4Zr-6Mo in the Annealed temper — lower-strength, more ductile and dimensionally stable condition for stock that will be re-heat-treated or for less critical parts. Ti-6Al-2Sn-4Zr-6Mo Annealed has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 88% of titanium grades. Elongation at break is 13% and the elastic modulus is 114 GPa (16.5 Msi). Ti-6Al-2Sn-4Zr-6Mo Annealed has a density of 4.65 g/cm³ (0.168 lb/in³), heavier than 90% of titanium grades. It melts at 1,590°C (2,894 °F). STA is the default condition FabDigit quotes; Annealed is available on request or by drawing note.

Advantages

  • High strength — 950 MPa (138 ksi), better than 88% of titanium grades
  • High service temperature — 400°C (752 °F), better than 78% of titanium grades

Limitations

  • Low fracture toughness — 40 MPa·√m (36.4 ksi·√in), worse than 99% of titanium grades
  • Difficult to weld — 30/100, worse than 98% of titanium grades
  • Poor heat conductor — 6.6 W/m·K (3.81 BTU/hr·ft·°F), worse than 97% of titanium grades
  • Low electrical conductivity — 1 % IACS, worse than 89% of titanium grades
  • Limited formability — 16/100, worse than 89% of titanium grades

Ti-6Al-2Sn-4Zr-6Mo Annealed properties

Typical room-temperature values for Ti-6Al-2Sn-4Zr-6Mo Annealed; 10 are specific to this condition. Other listed values are Ti-6Al-2Sn-4Zr-6Mo reference data and may not represent this condition. Bars are the position among titanium grades.

Physical3

Ti-6Al-2Sn-4Zr-6Mo Annealed has a density of 4.65 g/cm³ (0.168 lb/in³), heavier than 90% of titanium grades. It melts at 1,590°C (2,894 °F).

Density4.65 g/cm³0.17 lb/in³
Melting Point (Solidus)1,590°C2,894 °F
Liquidus Temperature1,650°C3,002 °F

Mechanical16

Ti-6Al-2Sn-4Zr-6Mo Annealed has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 88% of titanium grades. Elongation at break is 13% and the elastic modulus is 114 GPa (16.5 Msi).

Elastic (Young's) Modulus114 GPa16.5 Msi
Shear Modulus43 GPa6.2 Msi
Bulk Modulus112 GPa16.2 Msi
Poisson's Ratio0.33
Tensile Strength (Ultimate)1,030 MPa149 ksi
Yield Strength (0.2% offset)950 MPa138 ksi
Elongation at Break13%
Reduction in Area30%
Compressive Strength1,180 MPa171 ksi
Shear Strength720 MPa104 ksi
Fatigue Strength (Endurance Limit)500 MPa72.5 ksi
Fracture Toughness (K_IC)40 MPa·√m36.4 ksi·√in
Charpy V-Notch Impact (RT)12 J8.9 ft·lbf
Hardness, Brinell320 HB
Hardness, Rockwell C34 HRC
Hardness, Vickers370 HV

Thermal6

Ti-6Al-2Sn-4Zr-6Mo Annealed is rated for continuous service to 400°C (752 °F). It conducts heat at 6.6 W/m·K (3.81 BTU/hr·ft·°F), worse than 97% of titanium grades. Thermal expansion is 8 µm/m·K (4.44 µin/in·°F).

Thermal Conductivity6.6 W/m·K3.8 BTU/hr·ft·°F
Specific Heat Capacity480 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)8 µm/m·K4.4 µin/in·°F
Latent Heat of Fusion365 J/g157 BTU/lb
Max Service Temperature (continuous)400°C752 °F
Min Service Temperature-196°C-321 °F

Electrical3

Ti-6Al-2Sn-4Zr-6Mo Annealed conducts electricity at 1 % IACS, worse than 89% of titanium grades.

Electrical Conductivity1 % IACS
Electrical Resistivity1.8×10⁻⁶ Ω·m70.9 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is excellent (88/100), worse than 77% of titanium grades.

Galvanic Potential (seawater, vs SCE)-0.1 V
Corrosion ResistanceExcellent88/100
Chemical Resistance SummaryExcellent in seawater, oxidizing acids, chlorides and most organics thanks to the passive oxide; attacked by HF, hot concentrated HCl/H2SO4/phosphoric acid, and dry chlorine; risk of hydrogen pickup in reducing acids and of stress-corrosion in hot chloride/methanol.

Sustainability4

Producing a kilogram of Ti-6Al-2Sn-4Zr-6Mo Annealed takes about 700 MJ of energy and emits 42 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 25%.

Embodied Energy (primary production)700 MJ/kg300,946 BTU/lb
Embodied Carbon (primary production)42 kg CO₂/kg
Embodied Water1,000 L/kg120 gal/lb
Typical Recycled Content25%

Manufacturability7

Ti-6Al-2Sn-4Zr-6Mo Annealed's machinability is poor (18/100, worse than 83% of titanium grades); weldability poor (30/100); formability poor (16/100).

MachinabilityPoor18/100
Machinability Rating (AISI 1212 = 100 %)12%
WeldabilityPoor30/100
Formability (cold)Poor16/100
Brazeability / SolderabilityFair35/100
PolishabilityVery good70/100
Anodizing Responsefair — takes decorative/anti-gall Ti anodic oxide (colour by film thickness) and can be chemically converted; no hard-coat comparable to aluminium.

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Ti-6Al-2Sn-4Zr-6Mo Annealed

Is Ti-6Al-2Sn-4Zr-6Mo easy to machine?

Machine rigid with sharp uncoated-carbide or coated carbide tools, low speed (~15–25 m/min in STA), heavy positive rake, generous high-pressure flood coolant; never dwell — work hardening and fire risk from fine chips.

Can Ti-6Al-2Sn-4Zr-6Mo be welded?

GTAW/EBW/LBW possible under high-purity inert gas or vacuum, but the aged microstructure is destroyed locally — full post-weld solution + age is needed and welded joints are avoided in rotating parts.

Can Ti-6Al-2Sn-4Zr-6Mo be formed, bent or molded?

Essentially a hot-working alloy: forge/roll just below the ~940 °C beta transus with controlled strain rate; cold forming is limited to gentle bends with large radii in the solution-treated state.

What surface finishes work on Ti-6Al-2Sn-4Zr-6Mo?

Chemically mill or pickle in HNO3/HF to strip alpha case after hot work; shot peen for fatigue life; decorative/anti-fret anodize or ion nitriding are the usual surface treatments — avoid cadmium and silver plating (embrittlement).

Ti-6Al-2Sn-4Zr-6Mo 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.

ElementSpec limit (wt %)Nominal
Alalpha stabilizer5.5 – 6.56
Sn1.75 – 2.252
Zr3.5 – 4.54
Mobeta stabilizer, gives high hardenability5.5 – 6.56
Fe≤ 0.150.05
O≤ 0.150.11
C≤ 0.040.02
N≤ 0.040.01
H0.015 max for some product forms≤ 0.010.01
Yrotor-grade limit≤ 0.01—
Other, eachresiduals total 0.40 max≤ 0.1—
Tibalance—

Ti-6Al-2Sn-4Zr-6Mo Annealed — frequently asked

What is Ti-6Al-2Sn-4Zr-6Mo Annealed used for?

Ti-6Al-2Sn-4Zr-6Mo Annealed is typically used for turbine compressor disks, compressor blades and high-strength airframe forgings. In short: strongest alpha-beta forging alloy; 400 °C service capability; hardest to machine of family.

What is the yield strength of Ti-6Al-2Sn-4Zr-6Mo Annealed?

Ti-6Al-2Sn-4Zr-6Mo Annealed has a typical yield strength of 950 MPa (138 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 88% of titanium grades. Strength varies by condition: see the 5 listed tempers.

Is Ti-6Al-2Sn-4Zr-6Mo Annealed easy to machine?

Not especially — machinability is rated poor (18/100, worse than 83% of titanium grades). Machine rigid with sharp uncoated-carbide or coated carbide tools, low speed (~15–25 m/min in STA), heavy positive rake, generous high-pressure flood coolant; never dwell — work hardening and fire risk from fine chips.

Can Ti-6Al-2Sn-4Zr-6Mo Annealed be welded?

Not readily — weldability is rated poor (30/100). GTAW/EBW/LBW possible under high-purity inert gas or vacuum, but the aged microstructure is destroyed locally — full post-weld solution + age is needed and welded joints are avoided in rotating parts.

What surface finishes work on Ti-6Al-2Sn-4Zr-6Mo Annealed?

Chemically mill or pickle in HNO3/HF to strip alpha case after hot work; shot peen for fatigue life; decorative/anti-fret anodize or ion nitriding are the usual surface treatments — avoid cadmium and silver plating (embrittlement).

Can Ti-6Al-2Sn-4Zr-6Mo Annealed be formed, bent or molded?

Essentially a hot-working alloy: forge/roll just below the ~940 °C beta transus with controlled strain rate; cold forming is limited to gentle bends with large radii in the solution-treated state.

What is the maximum service temperature of Ti-6Al-2Sn-4Zr-6Mo Annealed?

Ti-6Al-2Sn-4Zr-6Mo Annealed is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between Ti-6Al-2Sn-4Zr-6Mo-STA and Ti-6Al-2Sn-4Zr-6Mo-ST?

STA is the default condition — standard supply condition for bar, billet and forgings: highest strength for compressor disks, blades and high-load fittings up to ~400 °C. ST: intermediate softer condition used for machining or hot working before the final aging cycle. Yield strength is 1,100 MPa in STA versus 900 MPa in ST.

Sources

  1. AMS 4981 — Titanium Alloy Bars, Forgings and Rings 6Al-2Sn-4Zr-6Mo, Solution and Precipitation Heat Treated — SAE International (2018)
  2. Materials Properties Handbook: Titanium Alloys — ASM International (1994)
  3. ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
  4. ASTM B348 / UNS R56260 designation data — ASTM International (2021)

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.