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Titanium Grade 3 vs Grade 7

Titanium · grade comparison

Titanium Grade 3 and Grade 7 are both titanium grades, both corrosion resistant ti. Grade 3 is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 320 MPa (46.4 ksi) for Grade 7, about 31% more; tensile strength follows at 500 MPa (72.5 ksi) vs 400 MPa (58 ksi). In exchange, Grade 7 is the more ductile: elongation 24% versus 20% for Grade 3, and Grade 3 is harder (200 HB vs 160 HB).

Grade 3Choose it when strength drives the design.

Grade 7Choose it when the part is bent, formed or impact-loaded.

Grade 3 vs Grade 7: properties

Grade 3Grade 7

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

500 MPa72.5 ksi
400 MPa58 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
320 MPa46.4 ksi

Elongation at Break

20%
24%

Reduction in Area

35%
45%

Compressive Strength

450 MPa65.3 ksi
340 MPa49.3 ksi

Shear Strength

380 MPa55.1 ksi
290 MPa42.1 ksi

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
215 MPa31.2 ksi

Charpy V-Notch Impact (RT)

24 J17.7 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

200 HB
160 HB

Hardness, Rockwell B

93 HRB
80 HRB

Hardness, Vickers

210 HV
170 HV

Same in both: Elastic (Young's) Modulus 103 GPa14.9 Msi · Shear Modulus 45 GPa6.5 Msi · Bulk Modulus 110 GPa16 Msi · Poisson's Ratio 0.34 · Fracture Toughness (K_IC) 70 MPa·√m63.7 ksi·√in

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,660°C3,020 °F
1,665°C3,029 °F

Liquidus Temperature

1,668°C3,034 °F
1,670°C3,038 °F

Same in both: Density 4.51 g/cm³0.16 lb/in³

Thermal

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

Latent Heat of Fusion

300 J/g129 BTU/lb
295 J/g127 BTU/lb

Max Service Temperature (continuous)

300°C572 °F
315°C599 °F

Same in both: Thermal Conductivity 16.4 W/m·K9.5 BTU/hr·ft·°F · Specific Heat Capacity 523 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 8.6 µm/m·K4.8 µin/in·°F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

5.5×10⁻⁷ Ω·m21.7 µΩ·in
5.6×10⁻⁷ Ω·m22 µΩ·in

Same in both: Electrical Conductivity 3.1 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

92 / 100
96 / 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 Rating (AISI 1212 = 100 %)

28%
30%

Formability (cold)

55 / 100
75 / 100

Castability

35 / 100
25 / 100

Same in both: Machinability 35 / 100 · Weldability 85 / 100 · Brazeability / Solderability 40 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

690 MJ/kg296,647 BTU/lb
700 MJ/kg300,946 BTU/lb

Embodied Carbon (primary production)

46 kg CO₂/kg
45 kg CO₂/kg

Embodied Water

1,000 L/kg120 gal/lb
800 L/kg95.9 gal/lb

Same in both: Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

111 kN·m/kg
89 kN·m/kg

Modulus of Resilience

856 kJ/m³
497 kJ/m³

Thermal Shock Resistance Index

9
7

Same in both: Specific Stiffness (E / density) 22.8 MN·m/kg · Thermal Diffusivity 7 mm²/s

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 scaleGrade 3Grade 7

Manufacturing and finishing

CapabilityGrade 3Grade 7
Default conditionOO
Relative cost$$$$$ Specialty$$$$$ Specialty
Min. machined wall1 mm1 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining and Sheet metal. Both take the same 20 finishes: AlCrN, AlTiN, Anodizing Type II, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, CrN, DLC, Electropolishing, HVOF Coating, MoS2 and 8 more.

Grade 3 vs Grade 7 — frequently asked

Is Grade 3 stronger than Grade 7?

Yes. Grade 3 has a typical yield strength of 420 MPa (60.9 ksi) against 320 MPa (46.4 ksi) for Grade 7 — about 31% more. Tensile strength is 500 MPa (72.5 ksi) vs 400 MPa (58 ksi).

Which is cheaper, Grade 3 or Grade 7?

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

When should I choose Grade 3 over Grade 7?

Pick Grade 3 when strength drives the design. Pick Grade 7 when the part is bent, formed or impact-loaded.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Grade 3 and Grade 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.