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Titanium ERTi-3 vs ERTi-7

Titanium · grade comparison

Titanium ERTi-3 and ERTi-7 are both titanium grades. ERTi-3 is the stronger of the two: yield strength 440 MPa (63.8 ksi) against 330 MPa (47.9 ksi) for ERTi-7, about 33% more; tensile strength follows at 520 MPa (75.4 ksi) vs 420 MPa (60.9 ksi). In exchange, ERTi-7 is the more ductile: elongation 24% versus 20% for ERTi-3, and ERTi-3 is harder (205 HB vs 155 HB). On the shop floor, ERTi-7 machines more easily (fair vs poor).

ERTi-3Choose it when strength drives the design.

ERTi-7Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

ERTi-3 vs ERTi-7: properties

ERTi-3ERTi-7

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

105 GPa15.2 Msi
103 GPa14.9 Msi

Tensile Strength (Ultimate)

520 MPa75.4 ksi
420 MPa60.9 ksi

Yield Strength (0.2% offset)

440 MPa63.8 ksi
330 MPa47.9 ksi

Elongation at Break

20%
24%

Reduction in Area

38%
45%

Compressive Strength

460 MPa66.7 ksi
350 MPa50.8 ksi

Shear Strength

370 MPa53.7 ksi
275 MPa39.9 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
210 MPa30.5 ksi

Fracture Toughness (K_IC)

66 MPa·√m60.1 ksi·√in
80 MPa·√m72.8 ksi·√in

Charpy V-Notch Impact (RT)

22 J16.2 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

205 HB
155 HB

Hardness, Rockwell B

93 HRB
80 HRB

Hardness, Vickers

215 HV
165 HV

Same in both: Shear Modulus 45 GPa6.5 Msi · Bulk Modulus 110 GPa16 Msi · Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Same in both: Density 4.51 g/cm³0.16 lb/in³ · Melting Point (Solidus) 1,660°C3,020 °F · Liquidus Temperature 1,670°C3,038 °F

Thermal

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

Thermal Conductivity

16 W/m·K9.2 BTU/hr·ft·°F
16.4 W/m·K9.5 BTU/hr·ft·°F

Specific Heat Capacity

540 J/kg·K0.13 BTU/lb·°F
523 J/kg·K0.12 BTU/lb·°F

Latent Heat of Fusion

323 J/g139 BTU/lb
325 J/g140 BTU/lb

Max Service Temperature (continuous)

300°C572 °F
315°C599 °F

Min Service Temperature

-250°C-418 °F
-196°C-321 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 8.6 µm/m·K4.8 µin/in·°F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.6×10⁻⁷ Ω·m22 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

93 / 100
95 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V

Manufacturability

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

Machinability

28 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
35%

Formability (cold)

55 / 100
75 / 100

Brazeability / Solderability

35 / 100
45 / 100

Same in both: Weldability 92 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

660 MJ/kg283,749 BTU/lb
720 MJ/kg309,545 BTU/lb

Embodied Carbon (primary production)

40 kg CO₂/kg
48 kg CO₂/kg

Typical Recycled Content

20%
10%

Same in both: Embodied Water 500 L/kg59.9 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

115 kN·m/kg
93 kN·m/kg

Specific Stiffness (E / density)

23.3 MN·m/kg
22.8 MN·m/kg

Modulus of Resilience

922 kJ/m³
529 kJ/m³

Thermal Diffusivity

6.6 mm²/s
7 mm²/s

Thermal Shock Resistance Index

9
8

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 scaleERTi-7ERTi-3

Manufacturing and finishing

CapabilityERTi-3ERTi-7
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Both take the same 1 finish: Plasma Spray.

ERTi-3 vs ERTi-7 — frequently asked

Is ERTi-3 stronger than ERTi-7?

Yes. ERTi-3 has a typical yield strength of 440 MPa (63.8 ksi) against 330 MPa (47.9 ksi) for ERTi-7 — about 33% more. Tensile strength is 520 MPa (75.4 ksi) vs 420 MPa (60.9 ksi).

Which is cheaper, ERTi-3 or ERTi-7?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, ERTi-3 or ERTi-7?

ERTi-7. Its machinability rates fair (40/100) against poor (28/100) for ERTi-3.

Ready to make it?

Upload a CAD file and FabDigit prices the part in ERTi-3 and ERTi-7 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.