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Titanium Ti-15Mo-2.7Nb-3Al-0.2Si-ST vs Ti-15Mo-2.7Nb-3Al-0.2Si STA-595

Titanium · Ti-15Mo-2.7Nb-3Al-0.2Si temper comparison

Ti-15Mo-2.7Nb-3Al-0.2Si-ST and Ti-15Mo-2.7Nb-3Al-0.2Si STA-595 are two conditions of the same titanium grade, Ti-15Mo-2.7Nb-3Al-0.2Si: ST (solution annealed) versus STA-595 (STA 595 °C). The chemistry is identical, so every difference below comes from the condition. Ti-15Mo-2.7Nb-3Al-0.2Si STA-595 is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 810 MPa (117 ksi) for Ti-15Mo-2.7Nb-3Al-0.2Si-ST, about 30% more; tensile strength follows at 1,140 MPa (165 ksi) vs 840 MPa (122 ksi). In exchange, Ti-15Mo-2.7Nb-3Al-0.2Si-ST is the more ductile: elongation 18% versus 9% for Ti-15Mo-2.7Nb-3Al-0.2Si STA-595, and Ti-15Mo-2.7Nb-3Al-0.2Si STA-595 is harder (37 HRC vs 28 HRC). Ti-15Mo-2.7Nb-3Al-0.2Si STA-595 is stiffer (98 GPa vs 80 GPa) and Ti-15Mo-2.7Nb-3Al-0.2Si STA-595 runs hotter in service (595°C vs 480°C continuous).

Ti-15Mo-2.7Nb-3Al-0.2Si-STChoose it when the part is bent, formed or impact-loaded.

Ti-15Mo-2.7Nb-3Al-0.2Si STA-595Choose it when strength drives the design, or when the part sees heat.

Ti-15Mo-2.7Nb-3Al-0.2Si-ST vs Ti-15Mo-2.7Nb-3Al-0.2Si STA-595: properties

Ti-15Mo-2.7Nb-3Al-0.2Si-STTi-15Mo-2.7Nb-3Al-0.2Si STA-595

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

80 GPa11.6 Msi
98 GPa14.2 Msi

Tensile Strength (Ultimate)

840 MPa122 ksi
1,140 MPa165 ksi

Yield Strength (0.2% offset)

810 MPa117 ksi
1,050 MPa152 ksi

Elongation at Break

18%
9%

Reduction in Area

40%
25%

Fatigue Strength (Endurance Limit)

450 MPa65.3 ksi
560 MPa81.2 ksi

Fracture Toughness (K_IC)

65 MPa·√m59.2 ksi·√in
45 MPa·√m41 ksi·√in

Hardness, Rockwell C

28 HRC
37 HRC

Hardness, Vickers

285 HV
360 HV

Same in both: Shear Modulus 30 GPa4.4 Msi · Bulk Modulus 79 GPa11.5 Msi · Poisson's Ratio 0.33 · Compressive Strength 840 MPa122 ksi · Shear Strength 520 MPa75.4 ksi

Physical

Density and transition temperatures.

Same in both: Density 4.94 g/cm³0.18 lb/in³ · Melting Point (Solidus) 1,600°C2,912 °F · Liquidus Temperature 1,650°C3,002 °F

Thermal

How each material carries heat and how hot it can run.

Max Service Temperature (continuous)

480°C896 °F
595°C1,103 °F

Same in both: Thermal Conductivity 7.6 W/m·K4.4 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 7.7 µm/m·K4.3 µin/in·°F · Latent Heat of Fusion 360 J/g155 BTU/lb · Min Service Temperature -70°C-94 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 1.3 % IACS · Electrical Resistivity 1.35×10⁻⁶ Ω·m53.1 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V · Corrosion Resistance 92 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

20 / 100
16 / 100

Formability (cold)

75 / 100
30 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 15% · Weldability 60 / 100 · Castability 30 / 100 · Brazeability / Solderability 45 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 700 MJ/kg300,946 BTU/lb · Embodied Carbon (primary production) 42 kg CO₂/kg · Embodied Water 550 L/kg65.9 gal/lb · Typical Recycled Content 15%

Strength versus weight

Yield strength against density for every titanium grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

3005007001,0004.555.5Density (g/cm³)Yield strength (MPa) — log scaleTi-15Mo-2.7Nb-3Al-0.2Si

Ti-15Mo-2.7Nb-3Al-0.2Si-ST vs Ti-15Mo-2.7Nb-3Al-0.2Si STA-595 — frequently asked

Is Ti-15Mo-2.7Nb-3Al-0.2Si STA-595 stronger than Ti-15Mo-2.7Nb-3Al-0.2Si-ST?

Yes. Ti-15Mo-2.7Nb-3Al-0.2Si STA-595 has a typical yield strength of 1,050 MPa (152 ksi) against 810 MPa (117 ksi) for Ti-15Mo-2.7Nb-3Al-0.2Si-ST — about 30% more. Tensile strength is 1,140 MPa (165 ksi) vs 840 MPa (122 ksi).

Which condition does FabDigit quote by default, ST or STA-595?

ST is the default Ti-15Mo-2.7Nb-3Al-0.2Si condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

When should I choose Ti-15Mo-2.7Nb-3Al-0.2Si-ST over Ti-15Mo-2.7Nb-3Al-0.2Si STA-595?

Pick Ti-15Mo-2.7Nb-3Al-0.2Si-ST when the part is bent, formed or impact-loaded. Pick Ti-15Mo-2.7Nb-3Al-0.2Si STA-595 when strength drives the design, or when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Ti-15Mo-2.7Nb-3Al-0.2Si-ST and Ti-15Mo-2.7Nb-3Al-0.2Si STA-595 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.