Titanium OT4-HR vs OT4-SR
Titanium · OT4 temper comparison
OT4-HR and OT4-SR are two conditions of the same titanium grade, OT4: HR (hot rolled) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. Both yield at about 690 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (hot rolled versus stress relieved). OT4-SR is the more ductile: elongation 15% versus 13% for OT4-HR, and OT4-HR is harder (25 HRC vs 23 HRC). OT4-SR runs hotter in service (350°C vs 300°C continuous).
OT4-SRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
OT4-HR vs OT4-SR: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all titanium grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all titanium grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 115 GPa16.7 Msi · Shear Modulus 43 GPa6.2 Msi · Bulk Modulus 110 GPa16 Msi · Poisson's Ratio 0.32
Physical
Density and transition temperatures.
Same in both: Density 4.55 g/cm³0.16 lb/in³ · Melting Point (Solidus) 1,620°C2,948 °F · Liquidus Temperature 1,665°C3,029 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 9.5 W/m·K5.5 BTU/hr·ft·°F · Specific Heat Capacity 540 J/kg·K0.13 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 8.6 µm/m·K4.8 µin/in·°F · Latent Heat of Fusion 365 J/g157 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 1.1 % IACS · Electrical Resistivity 1.55×10⁻⁶ Ω·m61 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Brazeability / Solderability 45 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 620 MJ/kg266,552 BTU/lb · Embodied Carbon (primary production) 38 kg CO₂/kg · Embodied Water 400 L/kg47.9 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.
OT4-HR vs OT4-SR — frequently asked
What is the difference between OT4-HR and OT4-SR?
OT4-HR and OT4-SR are two conditions of the same titanium grade, OT4: HR (hot rolled) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. Both yield at about 690 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (hot rolled versus stress relieved).
Which condition does FabDigit quote by default, HR or SR?
M is the default OT4 condition in the FabDigit quote flow (neither HR nor SR). 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 OT4-HR over OT4-SR?
Pick OT4-SR when the part is bent, formed or impact-loaded, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in OT4-HR and OT4-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.