Titanium Ti-3Al-8V-6Cr-4Mo-4Zr-ST vs Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA
Titanium · Ti-3Al-8V-6Cr-4Mo-4Zr temper comparison
Ti-3Al-8V-6Cr-4Mo-4Zr-ST and Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA are two conditions of the same titanium grade, Ti-3Al-8V-6Cr-4Mo-4Zr: ST (solution annealed) versus STA-OA (solution treated + over-aged (≈565–620 °C) for toughness). The chemistry is identical, so every difference below comes from the condition. Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA is the stronger of the two: yield strength 1,060 MPa (154 ksi) against 850 MPa (123 ksi) for Ti-3Al-8V-6Cr-4Mo-4Zr-ST, about 25% more; tensile strength follows at 1,130 MPa (164 ksi) vs 900 MPa (131 ksi). In exchange, Ti-3Al-8V-6Cr-4Mo-4Zr-ST is the more ductile: elongation 18% versus 12% for Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA, and Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA is harder (37 HRC vs 32 HRC). Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA is stiffer (100 GPa vs 86 GPa) and Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA runs hotter in service (300°C vs 200°C continuous). On the shop floor, Ti-3Al-8V-6Cr-4Mo-4Zr-ST welds better (good vs fair).
Ti-3Al-8V-6Cr-4Mo-4Zr-STChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
Ti-3Al-8V-6Cr-4Mo-4Zr STA-OAChoose it when strength drives the design, or when the part sees heat.
Ti-3Al-8V-6Cr-4Mo-4Zr-ST vs Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA: 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-3Al-8V-6Cr-4Mo-4Zr-STTi-3Al-8V-6Cr-4Mo-4Zr STA-OA
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)
Charpy V-Notch Impact (RT)
Hardness, Rockwell C
Hardness, Vickers
Same in both: Shear Modulus 33 GPa4.8 Msi · Bulk Modulus 90 GPa13.1 Msi · Poisson's Ratio 0.32
Physical
Density and transition temperatures.
Same in both: Density 4.82 g/cm³0.17 lb/in³ · Melting Point (Solidus) 1,650°C3,002 °F · Liquidus Temperature 1,700°C3,092 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 9.4 µm/m·K5.2 µin/in·°F · Latent Heat of Fusion 365 J/g157 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 20 / 100 · Brazeability / Solderability 35 / 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) 45 kg CO₂/kg · Embodied Water 800 L/kg95.9 gal/lb · Typical Recycled Content 25%
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-3Al-8V-6Cr-4Mo-4Zr-ST vs Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA — frequently asked
Is Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA stronger than Ti-3Al-8V-6Cr-4Mo-4Zr-ST?
Yes. Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA has a typical yield strength of 1,060 MPa (154 ksi) against 850 MPa (123 ksi) for Ti-3Al-8V-6Cr-4Mo-4Zr-ST — about 25% more. Tensile strength is 1,130 MPa (164 ksi) vs 900 MPa (131 ksi).
Which condition does FabDigit quote by default, ST or STA-OA?
ST is the default Ti-3Al-8V-6Cr-4Mo-4Zr 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 welds better, Ti-3Al-8V-6Cr-4Mo-4Zr-ST or Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA?
Ti-3Al-8V-6Cr-4Mo-4Zr-ST. Its weldability rates good (60/100) against fair (35/100) for Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Ti-3Al-8V-6Cr-4Mo-4Zr-ST and Ti-3Al-8V-6Cr-4Mo-4Zr STA-OA 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.