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Titanium Grade 9 vs Ti-6Al-7Nb

Titanium · grade comparison

Titanium Grade 9 and Ti-6Al-7Nb are both titanium grades. Ti-6Al-7Nb is the stronger of the two: yield strength 900 MPa (131 ksi) against 570 MPa (82.7 ksi) for Grade 9, about 58% more; tensile strength follows at 1,000 MPa (145 ksi) vs 690 MPa (100 ksi). In exchange, Grade 9 is the more ductile: elongation 20% versus 13% for Ti-6Al-7Nb, and Ti-6Al-7Nb is harder (305 HB vs 250 HB). Ti-6Al-7Nb runs hotter in service (350°C vs 300°C continuous). On the shop floor, Grade 9 welds better (very good vs good).

Grade 9Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

Ti-6Al-7NbChoose it when strength drives the design, or when the part sees heat.

Grade 9 vs Ti-6Al-7Nb: properties

Grade 9Ti-6Al-7Nb

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

100 GPa14.5 Msi
105 GPa15.2 Msi

Shear Modulus

44 GPa6.4 Msi
42 GPa6.1 Msi

Bulk Modulus

107 GPa15.5 Msi
110 GPa16 Msi

Poisson's Ratio

0.3
0.34

Tensile Strength (Ultimate)

690 MPa100 ksi
1,000 MPa145 ksi

Yield Strength (0.2% offset)

570 MPa82.7 ksi
900 MPa131 ksi

Elongation at Break

20%
13%

Reduction in Area

38%
45%

Compressive Strength

600 MPa87 ksi
950 MPa138 ksi

Shear Strength

450 MPa65.3 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

450 MPa65.3 ksi
550 MPa79.8 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
24 J17.7 ft·lbf

Hardness, Brinell

250 HB
305 HB

Hardness, Rockwell C

24 HRC
32 HRC

Hardness, Vickers

260 HV
320 HV

Same in both: Fracture Toughness (K_IC) 70 MPa·√m63.7 ksi·√in

Physical

Density and transition temperatures.

Density

4.48 g/cm³0.16 lb/in³
4.52 g/cm³0.16 lb/in³

Melting Point (Solidus)

1,650°C3,002 °F
1,600°C2,912 °F

Liquidus Temperature

1,704°C3,099 °F
1,680°C3,056 °F

Thermal

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

Thermal Conductivity

7.6 W/m·K4.4 BTU/hr·ft·°F
7 W/m·K4 BTU/hr·ft·°F

Specific Heat Capacity

544 J/kg·K0.13 BTU/lb·°F
470 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

9.2 µm/m·K5.1 µin/in·°F
9 µm/m·K5 µin/in·°F

Latent Heat of Fusion

365 J/g157 BTU/lb
360 J/g155 BTU/lb

Max Service Temperature (continuous)

300°C572 °F
350°C662 °F

Min Service Temperature

-250°C-418 °F
-196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

1.4 % IACS
1.3 % IACS

Electrical Resistivity

1.26×10⁻⁶ Ω·m49.6 µΩ·in
1.3×10⁻⁶ Ω·m51.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

90 / 100
93 / 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
20 / 100

Machinability Rating (AISI 1212 = 100 %)

25%
20%

Weldability

80 / 100
65 / 100

Formability (cold)

60 / 100
30 / 100

Castability

30 / 100
35 / 100

Brazeability / Solderability

45 / 100
30 / 100

Polishability

70 / 100
80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

650 MJ/kg279,450 BTU/lb
700 MJ/kg300,946 BTU/lb

Embodied Carbon (primary production)

42 kg CO₂/kg
45 kg CO₂/kg

Embodied Water

350 L/kg41.9 gal/lb
600 L/kg71.9 gal/lb

Typical Recycled Content

25%
15%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

154 kN·m/kg
221 kN·m/kg

Specific Stiffness (E / density)

22.3 MN·m/kg
23.2 MN·m/kg

Modulus of Resilience

1,625 kJ/m³
3,857 kJ/m³

Thermal Diffusivity

3.1 mm²/s
3.3 mm²/s

Thermal Shock Resistance Index

6
7

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 9Ti-6Al-7Nb

Manufacturing and finishing

CapabilityGrade 9Ti-6Al-7Nb
CNC machiningYes—
Sheet metalYes—
Default conditionO—
Relative cost$$$$ High$$$$ High
Min. machined wall1 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Anodizing Type IIYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
CrNYes—
DLCYes—
ElectropolishingYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
TiAlNYes—
TiB2Yes—
TiCNYes—
TiNYes—
WC/CYes—

They share 1 finish: Plasma Spray.

Grade 9 vs Ti-6Al-7Nb — frequently asked

Is Ti-6Al-7Nb stronger than Grade 9?

Yes. Ti-6Al-7Nb has a typical yield strength of 900 MPa (131 ksi) against 570 MPa (82.7 ksi) for Grade 9 — about 58% more. Tensile strength is 1,000 MPa (145 ksi) vs 690 MPa (100 ksi).

Which is cheaper, Grade 9 or Ti-6Al-7Nb?

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, Grade 9 or Ti-6Al-7Nb?

Grade 9, by a small margin. Both rate poor for machinability — 28/100 against 20/100 for Ti-6Al-7Nb; for welding the order is Grade 9 first (very good, 80/100) then Ti-6Al-7Nb (good, 65/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Grade 9 and Ti-6Al-7Nb 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.