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Titanium Grade 3 vs Ti Grade 18

Titanium · grade comparison

Titanium Grade 3 and Ti Grade 18 are both titanium grades. Ti Grade 18 is the stronger of the two: yield strength 570 MPa (82.7 ksi) against 420 MPa (60.9 ksi) for Grade 3, about 36% more; tensile strength follows at 690 MPa (100 ksi) vs 500 MPa (72.5 ksi). Ti Grade 18 is harder — 240 HB against 200 HB for Grade 3 — which matters for wear surfaces and threads. Grade 3 conducts heat better (16.4 W/m·K vs 7.6 W/m·K). On the shop floor, Grade 3 machines more easily (fair vs poor) and Ti Grade 18 sits in a lower cost tier (high, $$$$) than Grade 3 (specialty, $$$$$).

Grade 3Choose it when the part is machined in volume.

Ti Grade 18Choose it when strength drives the design, or when surface hardness matters.

Grade 3 vs Ti Grade 18: properties

Grade 3Ti Grade 18

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

45 GPa6.5 Msi
44 GPa6.4 Msi

Bulk Modulus

110 GPa16 Msi
105 GPa15.2 Msi

Poisson's Ratio

0.34
0.32

Tensile Strength (Ultimate)

500 MPa72.5 ksi
690 MPa100 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
570 MPa82.7 ksi

Reduction in Area

35%
40%

Compressive Strength

450 MPa65.3 ksi
590 MPa85.6 ksi

Shear Strength

380 MPa55.1 ksi
420 MPa60.9 ksi

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
480 MPa69.6 ksi

Charpy V-Notch Impact (RT)

24 J17.7 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

200 HB
240 HB

Hardness, Rockwell B

93 HRB
—

Hardness, Vickers

210 HV
255 HV

Hardness, Rockwell C

—
24 HRC

Same in both: Elastic (Young's) Modulus 103 GPa14.9 Msi · Elongation at Break 20% · Fracture Toughness (K_IC) 70 MPa·√m63.7 ksi·√in

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,660°C3,020 °F
1,650°C3,002 °F

Liquidus Temperature

1,668°C3,034 °F
1,704°C3,099 °F

Thermal

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

Thermal Conductivity

16.4 W/m·K9.5 BTU/hr·ft·°F
7.6 W/m·K4.4 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

8.6 µm/m·K4.8 µin/in·°F
9.4 µm/m·K5.2 µin/in·°F

Latent Heat of Fusion

300 J/g129 BTU/lb
365 J/g157 BTU/lb

Max Service Temperature (continuous)

300°C572 °F
315°C599 °F

Min Service Temperature

-196°C-321 °F
-253°C-423 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

3.1 % IACS
1.4 % IACS

Electrical Resistivity

5.5×10⁻⁷ Ω·m21.7 µΩ·in
1.26×10⁻⁶ Ω·m49.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

92 / 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

35 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

28%
22%

Weldability

85 / 100
80 / 100

Formability (cold)

55 / 100
60 / 100

Brazeability / Solderability

40 / 100
45 / 100

Polishability

70 / 100
65 / 100

Same in both: Castability 35 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

690 MJ/kg296,647 BTU/lb
650 MJ/kg279,450 BTU/lb

Embodied Carbon (primary production)

46 kg CO₂/kg
42 kg CO₂/kg

Embodied Water

1,000 L/kg120 gal/lb
320 L/kg38.3 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
154 kN·m/kg

Specific Stiffness (E / density)

22.8 MN·m/kg
23 MN·m/kg

Modulus of Resilience

856 kJ/m³
1,577 kJ/m³

Thermal Diffusivity

7 mm²/s
3.1 mm²/s

Thermal Shock Resistance Index

9
5

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 3Ti Grade 18

Manufacturing and finishing

CapabilityGrade 3Ti Grade 18
CNC machiningYes—
Sheet metalYes—
Default conditionO—
Relative cost$$$$$ Specialty$$$$ 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 3 vs Ti Grade 18 — frequently asked

Is Ti Grade 18 stronger than Grade 3?

Yes. Ti Grade 18 has a typical yield strength of 570 MPa (82.7 ksi) against 420 MPa (60.9 ksi) for Grade 3 — about 36% more. Tensile strength is 690 MPa (100 ksi) vs 500 MPa (72.5 ksi).

Which is cheaper, Grade 3 or Ti Grade 18?

Ti Grade 18 is the lower-cost material: it sits in the high tier ($$$$) while Grade 3 is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, Grade 3 or Ti Grade 18?

Grade 3. Its machinability rates fair (35/100) against poor (25/100) for Ti Grade 18; for welding the order is Grade 3 first (excellent, 85/100) then Ti Grade 18 (very good, 80/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Grade 3 and Ti Grade 18 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.