Titanium Ti-15Mo-2.7Nb-3Al-0.2Si-ST vs Ti-15Mo-2.7Nb-3Al-0.2Si STA-538
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-538 are two conditions of the same titanium grade, Ti-15Mo-2.7Nb-3Al-0.2Si: ST (solution annealed) versus STA-538 (STA 538 °C). The chemistry is identical, so every difference below comes from the condition. Ti-15Mo-2.7Nb-3Al-0.2Si STA-538 is the stronger of the two: yield strength 1,210 MPa (175 ksi) against 810 MPa (117 ksi) for Ti-15Mo-2.7Nb-3Al-0.2Si-ST, about 49% more; tensile strength follows at 1,310 MPa (190 ksi) vs 840 MPa (122 ksi). In exchange, Ti-15Mo-2.7Nb-3Al-0.2Si-ST is the more ductile: elongation 18% versus 6% for Ti-15Mo-2.7Nb-3Al-0.2Si STA-538, and Ti-15Mo-2.7Nb-3Al-0.2Si STA-538 is harder (41 HRC vs 28 HRC). Ti-15Mo-2.7Nb-3Al-0.2Si STA-538 is stiffer (103 GPa vs 80 GPa) and Ti-15Mo-2.7Nb-3Al-0.2Si STA-538 runs hotter in service (565°C vs 480°C continuous). On the shop floor, Ti-15Mo-2.7Nb-3Al-0.2Si-ST welds better (good vs fair).
Ti-15Mo-2.7Nb-3Al-0.2Si-STChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
Ti-15Mo-2.7Nb-3Al-0.2Si STA-538Choose 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-538: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all titanium grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all titanium grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Ti-15Mo-2.7Nb-3Al-0.2Si-STTi-15Mo-2.7Nb-3Al-0.2Si STA-538
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Rockwell C
Hardness, Vickers
Same in both: Shear Modulus 30 GPa4.4 Msi · Bulk Modulus 79 GPa11.5 Msi · Poisson's Ratio 0.33
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)
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
Weldability
Formability (cold)
Same in both: Machinability Rating (AISI 1212 = 100 %) 15% · 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.
Ti-15Mo-2.7Nb-3Al-0.2Si-ST vs Ti-15Mo-2.7Nb-3Al-0.2Si STA-538 — frequently asked
Is Ti-15Mo-2.7Nb-3Al-0.2Si STA-538 stronger than Ti-15Mo-2.7Nb-3Al-0.2Si-ST?
Yes. Ti-15Mo-2.7Nb-3Al-0.2Si STA-538 has a typical yield strength of 1,210 MPa (175 ksi) against 810 MPa (117 ksi) for Ti-15Mo-2.7Nb-3Al-0.2Si-ST — about 49% more. Tensile strength is 1,310 MPa (190 ksi) vs 840 MPa (122 ksi).
Which condition does FabDigit quote by default, ST or STA-538?
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.
Which is easier to machine, Ti-15Mo-2.7Nb-3Al-0.2Si-ST or Ti-15Mo-2.7Nb-3Al-0.2Si STA-538?
Ti-15Mo-2.7Nb-3Al-0.2Si-ST. Its machinability rates poor (20/100) against not recommended (14/100) for Ti-15Mo-2.7Nb-3Al-0.2Si STA-538; for welding the order is Ti-15Mo-2.7Nb-3Al-0.2Si-ST first (good, 60/100) then Ti-15Mo-2.7Nb-3Al-0.2Si STA-538 (fair, 35/100).
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-538 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.