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Titanium TC21-DA vs TC21-STA

Titanium · TC21 temper comparison

TC21-DA and TC21-STA are two conditions of the same titanium grade, TC21: DA (duplex (double) 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 1,000 MPa (145 ksi) for TC21-DA, about 6% more; tensile strength follows at 1,150 MPa (167 ksi) vs 1,090 MPa (158 ksi). In exchange, TC21-DA is the more ductile: elongation 12% versus 10% for TC21-STA, and TC21-STA is harder (38 HRC vs 36 HRC).

TC21-DAChoose it when the part is bent, formed or impact-loaded.

TC21-STAChoose it when strength drives the design.

TC21-DA vs TC21-STA: properties

TC21-DATC21-STA

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,090 MPa158 ksi
1,150 MPa167 ksi

Yield Strength (0.2% offset)

1,000 MPa145 ksi
1,060 MPa154 ksi

Elongation at Break

12%
10%

Reduction in Area

30%
25%

Fatigue Strength (Endurance Limit)

550 MPa79.8 ksi
570 MPa82.7 ksi

Fracture Toughness (K_IC)

68 MPa·√m61.9 ksi·√in
75 MPa·√m68.3 ksi·√in

Hardness, Brinell

335 HB
350 HB

Hardness, Rockwell C

36 HRC
38 HRC

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

18 / 100
16 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 18% · Weldability 50 / 100 · Formability (cold) 18 / 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.

3005007001,0004.555.5Density (g/cm³)Yield strength (MPa) — log scaleTC21

TC21-DA vs TC21-STA — frequently asked

Is TC21-STA stronger than TC21-DA?

Yes. TC21-STA has a typical yield strength of 1,060 MPa (154 ksi) against 1,000 MPa (145 ksi) for TC21-DA — about 6% more. Tensile strength is 1,150 MPa (167 ksi) vs 1,090 MPa (158 ksi).

Which condition does FabDigit quote by default, DA 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-DA over TC21-STA?

Pick TC21-DA 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-DA 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.