Titanium Ti-5553-O vs Ti-5553-ST
Titanium · Ti-5553 temper comparison
Ti-5553-O and Ti-5553-ST are two conditions of the same titanium grade, Ti-5553: O (annealed) versus ST (solution annealed). The chemistry is identical, so every difference below comes from the condition. Ti-5553-O is the stronger of the two: yield strength 900 MPa (131 ksi) against 830 MPa (120 ksi) for Ti-5553-ST, about 8% more; tensile strength follows at 960 MPa (139 ksi) vs 890 MPa (129 ksi). In exchange, Ti-5553-ST is the more ductile: elongation 20% versus 16% for Ti-5553-O, and Ti-5553-O is harder (33 HRC vs 30 HRC). Ti-5553-O is stiffer (105 GPa vs 98 GPa) and Ti-5553-O runs hotter in service (300°C vs 200°C continuous).
Ti-5553-OChoose it when strength drives the design, or when the part sees heat.
Ti-5553-STChoose it when the part is bent, formed or impact-loaded.
Ti-5553-O vs Ti-5553-ST: 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.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Rockwell C
Hardness, Vickers
Same in both: Shear Modulus 40 GPa5.8 Msi · Bulk Modulus 105 GPa15.2 Msi · Poisson's Ratio 0.33 · Compressive Strength 940 MPa136 ksi · Shear Strength 600 MPa87 ksi · Fatigue Strength (Endurance Limit) 480 MPa69.6 ksi · Hardness, Brinell 305 HB
Physical
Density and transition temperatures.
Same in both: Density 4.65 g/cm³0.17 lb/in³ · Melting Point (Solidus) 1,580°C2,876 °F · Liquidus Temperature 1,640°C2,984 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 7 W/m·K4 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 9.3 µm/m·K5.2 µin/in·°F · Latent Heat of Fusion 360 J/g155 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).
Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V · Corrosion Resistance 88 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Formability (cold)
Same in both: Machinability Rating (AISI 1212 = 100 %) 16% · Weldability 35 / 100 · Castability 25 / 100 · Brazeability / Solderability 30 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 650 MJ/kg279,450 BTU/lb · Embodied Carbon (primary production) 42 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.
Ti-5553-O vs Ti-5553-ST — frequently asked
Is Ti-5553-O stronger than Ti-5553-ST?
Yes. Ti-5553-O has a typical yield strength of 900 MPa (131 ksi) against 830 MPa (120 ksi) for Ti-5553-ST — about 8% more. Tensile strength is 960 MPa (139 ksi) vs 890 MPa (129 ksi).
Which condition does FabDigit quote by default, O or ST?
O is the default Ti-5553 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 Ti-5553-O over Ti-5553-ST?
Pick Ti-5553-O when strength drives the design, or when the part sees heat. Pick Ti-5553-ST when the part is bent, formed or impact-loaded.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Ti-5553-O and Ti-5553-ST 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.