Titanium Grade 9 vs IMI 550
Titanium · grade comparison
Titanium Grade 9 and IMI 550 are both titanium grades. IMI 550 is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 570 MPa (82.7 ksi) for Grade 9, about 84% more; tensile strength follows at 1,150 MPa (167 ksi) vs 690 MPa (100 ksi). In exchange, Grade 9 is the more ductile: elongation 20% versus 13% for IMI 550, and IMI 550 is harder (333 HB vs 250 HB). IMI 550 is stiffer (115 GPa vs 100 GPa) and IMI 550 runs hotter in service (400°C vs 300°C continuous). On the shop floor, Grade 9 machines more easily (28 vs 16 out of 100) and Grade 9 welds better (very good vs poor).
Grade 9Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
IMI 550Choose it when strength drives the design, or when the part sees heat.
Grade 9 vs IMI 550: 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
Poisson's Ratio
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 C
Hardness, Vickers
Same in both: Shear Modulus 44 GPa6.4 Msi · Bulk Modulus 107 GPa15.5 Msi
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Latent Heat of Fusion 365 J/g157 BTU/lb
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
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)
Castability
Brazeability / Solderability
Same in both: Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 650 MJ/kg279,450 BTU/lb · Embodied Carbon (primary production) 42 kg CO₂/kg
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | Grade 9 | IMI 550 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | O | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | 1 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| Anodizing Type II | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| Cerakote | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| Electropolishing | Yes | — |
| HVOF Coating | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| TiAlN | Yes | — |
| TiB2 | Yes | — |
| TiCN | Yes | — |
| TiN | Yes | — |
| WC/C | Yes | — |
They share 1 finish: Plasma Spray.
Grade 9 vs IMI 550 — frequently asked
Is IMI 550 stronger than Grade 9?
Yes. IMI 550 has a typical yield strength of 1,050 MPa (152 ksi) against 570 MPa (82.7 ksi) for Grade 9 — about 84% more. Tensile strength is 1,150 MPa (167 ksi) vs 690 MPa (100 ksi).
Which is cheaper, Grade 9 or IMI 550?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Grade 9 or IMI 550?
Grade 9, by a small margin. Both rate poor for machinability — 28/100 against 16/100 for IMI 550; for welding the order is Grade 9 first (very good, 80/100) then IMI 550 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Grade 9 and IMI 550 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.