Titanium TC21 Annealed vs TC21-STA
Titanium · TC21 temper comparison
TC21 Annealed and TC21-STA are two conditions of the same titanium grade, TC21: Annealed versus STA (solution treated and aged). The chemistry is identical, so every difference below comes from the condition. TC21-STA is the stronger of the two: yield strength 1,060 MPa (154 ksi) against 940 MPa (136 ksi) for TC21 Annealed, about 13% more; tensile strength follows at 1,150 MPa (167 ksi) vs 1,030 MPa (149 ksi). In exchange, TC21 Annealed is the more ductile: elongation 13% versus 10% for TC21-STA, and TC21-STA is harder (350 HB vs 315 HB).
TC21 AnnealedChoose it when the part is bent, formed or impact-loaded.
TC21-STAChoose it when strength drives the design.
TC21 Annealed vs TC21-STA: 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.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 114 GPa16.5 Msi · Shear Modulus 43 GPa6.2 Msi · Bulk Modulus 112 GPa16.2 Msi · Poisson's Ratio 0.33 · Compressive Strength 1,120 MPa162 ksi · Shear Strength 700 MPa102 ksi · Charpy V-Notch Impact (RT) 28 J20.7 ft·lbf · Hardness, Vickers 365 HV
Physical
Density and transition temperatures.
Same in both: Density 4.58 g/cm³0.17 lb/in³ · Melting Point (Solidus) 1,600°C2,912 °F · Liquidus Temperature 1,660°C3,020 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 7 W/m·K4 BTU/hr·ft·°F · Specific Heat Capacity 540 J/kg·K0.13 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 9 µm/m·K5 µin/in·°F · Latent Heat of Fusion 365 J/g157 BTU/lb · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 1 % IACS · Electrical Resistivity 1.7×10⁻⁶ Ω·m66.9 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
Formability (cold)
Same in both: Machinability Rating (AISI 1212 = 100 %) 18% · Weldability 50 / 100 · Brazeability / Solderability 40 / 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 400 L/kg47.9 gal/lb · Typical Recycled Content 20%
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.
TC21 Annealed vs TC21-STA — frequently asked
Is TC21-STA stronger than TC21 Annealed?
Yes. TC21-STA has a typical yield strength of 1,060 MPa (154 ksi) against 940 MPa (136 ksi) for TC21 Annealed — about 13% more. Tensile strength is 1,150 MPa (167 ksi) vs 1,030 MPa (149 ksi).
Which condition does FabDigit quote by default, Annealed or STA?
STA is the default TC21 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 TC21 Annealed over TC21-STA?
Pick TC21 Annealed when the part is bent, formed or impact-loaded. Pick TC21-STA when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in TC21 Annealed and TC21-STA 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.