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Titanium Grade 13 vs OT4

Titanium · grade comparison

Titanium Grade 13 and OT4 are both titanium grades. OT4 is the stronger of the two: yield strength 640 MPa (92.8 ksi) against 240 MPa (34.8 ksi) for Grade 13, about 167% more; tensile strength follows at 780 MPa (113 ksi) vs 345 MPa (50 ksi). In exchange, Grade 13 is the more ductile: elongation 28% versus 16% for OT4, and OT4 is harder (240 HB vs 130 HB). OT4 is stiffer (115 GPa vs 105 GPa) and OT4 runs hotter in service (350°C vs 300°C continuous). On the shop floor, Grade 13 machines more easily (fair vs poor) and Grade 13 welds better (excellent vs very good).

Grade 13Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

OT4Choose it when strength drives the design, or when the part sees heat.

Grade 13 vs OT4: properties

Grade 13OT4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

105 GPa15.2 Msi
115 GPa16.7 Msi

Shear Modulus

40 GPa5.8 Msi
43 GPa6.2 Msi

Poisson's Ratio

0.34
0.32

Tensile Strength (Ultimate)

345 MPa50 ksi
780 MPa113 ksi

Yield Strength (0.2% offset)

240 MPa34.8 ksi
640 MPa92.8 ksi

Elongation at Break

28%
16%

Reduction in Area

45%
35%

Compressive Strength

260 MPa37.7 ksi
690 MPa100 ksi

Shear Strength

240 MPa34.8 ksi
480 MPa69.6 ksi

Fatigue Strength (Endurance Limit)

190 MPa27.6 ksi
400 MPa58 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 ksi·√in
65 MPa·√m59.2 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

130 HB
240 HB

Hardness, Rockwell B

72 HRB
100 HRB

Hardness, Vickers

140 HV
250 HV

Hardness, Rockwell C

—
22 HRC

Same in both: Bulk Modulus 110 GPa16 Msi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,650°C3,002 °F
1,620°C2,948 °F

Liquidus Temperature

1,675°C3,047 °F
1,665°C3,029 °F

Thermal

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

Thermal Conductivity

17.5 W/m·K10.1 BTU/hr·ft·°F
9.5 W/m·K5.5 BTU/hr·ft·°F

Specific Heat Capacity

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

Max Service Temperature (continuous)

300°C572 °F
350°C662 °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 · Latent Heat of Fusion 365 J/g157 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

3.1 % IACS
1.1 % IACS

Electrical Resistivity

5.6×10⁻⁷ Ω·m22 µΩ·in
1.55×10⁻⁶ Ω·m61 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

93 / 100
88 / 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

38 / 100
28 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
25%

Weldability

88 / 100
72 / 100

Formability (cold)

72 / 100
55 / 100

Brazeability / Solderability

40 / 100
45 / 100

Polishability

70 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

660 MJ/kg283,749 BTU/lb
620 MJ/kg266,552 BTU/lb

Embodied Carbon (primary production)

45 kg CO₂/kg
38 kg CO₂/kg

Embodied Water

1,500 L/kg180 gal/lb
400 L/kg47.9 gal/lb

Same in both: Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

76 kN·m/kg
171 kN·m/kg

Specific Stiffness (E / density)

23.3 MN·m/kg
25.3 MN·m/kg

Modulus of Resilience

274 kJ/m³
1,781 kJ/m³

Thermal Diffusivity

7.5 mm²/s
3.9 mm²/s

Same in both: Thermal Shock Resistance Index 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 13OT4

Manufacturing and finishing

CapabilityGrade 13OT4
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Both take the same 1 finish: Plasma Spray.

Grade 13 vs OT4 — frequently asked

Is OT4 stronger than Grade 13?

Yes. OT4 has a typical yield strength of 640 MPa (92.8 ksi) against 240 MPa (34.8 ksi) for Grade 13 — about 167% more. Tensile strength is 780 MPa (113 ksi) vs 345 MPa (50 ksi).

Which is cheaper, Grade 13 or OT4?

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 13 or OT4?

Grade 13. Its machinability rates fair (38/100) against poor (28/100) for OT4; for welding the order is Grade 13 first (excellent, 88/100) then OT4 (very good, 72/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Grade 13 and OT4 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.