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Titanium IMI 550-HR vs IMI 550-STA

Titanium · IMI 550 temper comparison

IMI 550-HR and IMI 550-STA are two conditions of the same titanium grade, IMI 550: HR (hot rolled) versus STA (solution treated and aged). The chemistry is identical, so every difference below comes from the condition. IMI 550-STA is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 950 MPa (138 ksi) for IMI 550-HR, about 11% more; tensile strength follows at 1,150 MPa (167 ksi) vs 1,050 MPa (152 ksi). IMI 550-STA is harder — 333 HB against 313 HB for IMI 550-HR — which matters for wear surfaces and threads. IMI 550-STA runs hotter in service (400°C vs 350°C continuous).

IMI 550-STAChoose it when strength drives the design, or when surface hardness matters.

IMI 550-HR vs IMI 550-STA: properties

IMI 550-HRIMI 550-STA

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

114 GPa16.5 Msi
115 GPa16.7 Msi

Tensile Strength (Ultimate)

1,050 MPa152 ksi
1,150 MPa167 ksi

Yield Strength (0.2% offset)

950 MPa138 ksi
1,050 MPa152 ksi

Elongation at Break

12%
13%

Reduction in Area

28%
30%

Compressive Strength

1,010 MPa146 ksi
1,120 MPa162 ksi

Shear Strength

640 MPa92.8 ksi
690 MPa100 ksi

Fatigue Strength (Endurance Limit)

510 MPa74 ksi
580 MPa84.1 ksi

Fracture Toughness (K_IC)

52 MPa·√m47.3 ksi·√in
45 MPa·√m41 ksi·√in

Charpy V-Notch Impact (RT)

18 J13.3 ft·lbf
15 J11.1 ft·lbf

Hardness, Brinell

313 HB
333 HB

Hardness, Rockwell C

33 HRC
36 HRC

Hardness, Vickers

330 HV
350 HV

Same in both: Shear Modulus 44 GPa6.4 Msi · Bulk Modulus 107 GPa15.5 Msi · Poisson's Ratio 0.32

Physical

Density and transition temperatures.

Same in both: Density 4.6 g/cm³0.17 lb/in³ · Melting Point (Solidus) 1,590°C2,894 °F · Liquidus Temperature 1,650°C3,002 °F

Thermal

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

Thermal Conductivity

7.2 W/m·K4.2 BTU/hr·ft·°F
7.1 W/m·K4.1 BTU/hr·ft·°F

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Same in both: Specific Heat Capacity 565 J/kg·K0.13 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 9.4 µm/m·K5.2 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 1.65×10⁻⁶ Ω·m65 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V · Corrosion Resistance 85 / 100

Manufacturability

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

Machinability

18 / 100
16 / 100

Machinability Rating (AISI 1212 = 100 %)

20%
18%

Weldability

30 / 100
25 / 100

Formability (cold)

18 / 100
15 / 100

Same in both: Castability 20 / 100 · Brazeability / Solderability 35 / 100 · Polishability 70 / 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 500 L/kg59.9 gal/lb · Typical Recycled Content 20%

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 scaleIMI 550

IMI 550-HR vs IMI 550-STA — frequently asked

Is IMI 550-STA stronger than IMI 550-HR?

Yes. IMI 550-STA has a typical yield strength of 1,050 MPa (152 ksi) against 950 MPa (138 ksi) for IMI 550-HR — about 11% more. Tensile strength is 1,150 MPa (167 ksi) vs 1,050 MPa (152 ksi).

Which condition does FabDigit quote by default, HR or STA?

STA is the default IMI 550 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.

Which welds better, IMI 550-HR or IMI 550-STA?

IMI 550-HR. Its weldability rates poor (30/100) against poor (25/100) for IMI 550-STA.

Ready to make it?

Upload a CAD file and FabDigit prices the part in IMI 550-HR and IMI 550-STA 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.