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Titanium Grade 4-O vs Grade 4-SR

Titanium · Grade 4 temper comparison

Grade 4-O and Grade 4-SR are two conditions of the same titanium grade, Grade 4: O (annealed) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. Grade 4-SR is the stronger of the two: yield strength 590 MPa (85.6 ksi) against 550 MPa (79.8 ksi) for Grade 4-O, about 7% more; tensile strength follows at 660 MPa (95.7 ksi) vs 620 MPa (89.9 ksi). In exchange, Grade 4-O is the more ductile: elongation 20% versus 18% for Grade 4-SR, and Grade 4-SR is harder (280 HV vs 265 HV).

Grade 4-OChoose it when the part is bent, formed or impact-loaded.

Grade 4-SRChoose it when strength drives the design.

Grade 4-O vs Grade 4-SR: properties

Grade 4-OGrade 4-SR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
660 MPa95.7 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
590 MPa85.6 ksi

Elongation at Break

20%
18%

Reduction in Area

40%
36%

Compressive Strength

570 MPa82.7 ksi
610 MPa88.5 ksi

Shear Strength

420 MPa60.9 ksi
445 MPa64.5 ksi

Fatigue Strength (Endurance Limit)

340 MPa49.3 ksi
370 MPa53.7 ksi

Fracture Toughness (K_IC)

66 MPa·√m60.1 ksi·√in
60 MPa·√m54.6 ksi·√in

Charpy V-Notch Impact (RT)

22 J16.2 ft·lbf
18 J13.3 ft·lbf

Hardness, Brinell

253 HB
265 HB

Hardness, Rockwell B

100 HRB
103 HRB

Hardness, Vickers

265 HV
280 HV

Same in both: Elastic (Young's) Modulus 105 GPa15.2 Msi · 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 1,665°C3,029 °F

Thermal

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

Same in both: Thermal Conductivity 17.2 W/m·K9.9 BTU/hr·ft·°F · Specific Heat Capacity 540 J/kg·K0.13 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 9 µm/m·K5 µin/in·°F · Latent Heat of Fusion 365 J/g157 BTU/lb · Max Service Temperature (continuous) 300°C572 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V · Corrosion Resistance 92 / 100

Manufacturability

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

Formability (cold)

50 / 100
40 / 100

Same in both: Machinability 30 / 100 · Machinability Rating (AISI 1212 = 100 %) 25% · Weldability 80 / 100 · Castability 30 / 100 · Brazeability / Solderability 40 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 700 MJ/kg300,946 BTU/lb · Embodied Carbon (primary production) 45 kg CO₂/kg · Embodied Water 800 L/kg95.9 gal/lb · Typical Recycled Content 25%

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 4

Grade 4-O vs Grade 4-SR — frequently asked

Is Grade 4-SR stronger than Grade 4-O?

Yes. Grade 4-SR has a typical yield strength of 590 MPa (85.6 ksi) against 550 MPa (79.8 ksi) for Grade 4-O — about 7% more. Tensile strength is 660 MPa (95.7 ksi) vs 620 MPa (89.9 ksi).

Which condition does FabDigit quote by default, O or SR?

O is the default Grade 4 condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

When should I choose Grade 4-O over Grade 4-SR?

Pick Grade 4-O when the part is bent, formed or impact-loaded. Pick Grade 4-SR when strength drives the design.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Grade 4-O and Grade 4-SR 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.