Titanium (commercially pure, grades 1 to 4) CP Ti
Ti (unalloyed titanium, 99 to 99.5 % Ti overall). Composition maxima in weight % from the ATI tables: grade 1 Fe 0.20, O 0.18, C 0.08, N 0.03, H 0.015
Also known as UNS R50250, UNS R50400, UNS R50550, UNS R50700, ASTM B265
Commercially pure titanium is unalloyed titanium sold as ASTM grades 1 to 4, which differ in their limits on oxygen, iron, carbon, nitrogen and hydrogen.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Recipe, share of the weight
- Ti balanceTitanium
- O maximum, by grade (see identity formula)Oxygen
- Fe maximum, by grade (see identity formula)Iron
- C maximumCarbon
- N maximum, by grade (see identity formula)Nitrogen
- H maximum 0.015 in all four gradesHydrogen
Best for
Corrosion-resistant tubing and plumbing where strength is secondary; grade 1 is the most ductile (ATI minimum elongation 24 %)
Weakest at
Strength in the lower grades (grade 1 has a 138 MPa minimum yield strength, ATI), and ignition in oxygen-enriched gas (NASA)
Risk at a glance
- People Moderate. Mostly not classified
- If it fails High. Ignition and burning in oxygen-enriched gas
- Corrosion Low. A thin passive oxide layer protects titanium against oxidizing acids.
Quick facts: CP Ti
| Property | Value | Basis |
|---|---|---|
| Density | 4.51 g/cm³ | 5 sourced values across conditions |
| Yield strength | at least 138 MPa | 4 sourced values across conditions |
| Tensile strength | at least 240 MPa | 4 sourced values across conditions |
| Young's modulus | 116 GPa | 1 sourced value |
| Thermal conductivity | 21.9 W/(m·K) | 1 sourced value |
| Melting point | 1,668 °C | 1 sourced value |
| Specific heat | 520 J/(kg·K) | 1 sourced value |
What is the density of Titanium (CP Ti)?
Titanium (CP Ti) has a density of 4.51 g/cm³. The range covers 5 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the thermal conductivity of Titanium (CP Ti)?
Titanium (CP Ti) has a thermal conductivity of 21.9 W/(m·K). The source and test conditions are listed in the properties table on this page.
What is the melting point of Titanium (CP Ti)?
Titanium (CP Ti) has a melting point of 1,668 °C. The source and test conditions are listed in the properties table on this page.
What is the yield strength of Titanium (CP Ti)?
Titanium (CP Ti) has a yield strength of at least 138 MPa. The range covers 4 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the tensile strength of Titanium (CP Ti)?
Titanium (CP Ti) has a tensile strength of at least 240 MPa. The range covers 4 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What are the other names and codes for Titanium (CP Ti)?
Titanium (CP Ti) is also written as UNS R50250, UNS R50400, UNS R50550, UNS R50700, ASTM B265. Each code is printed in the source listed beside it in the designations table.
What is Titanium (CP Ti) used for?
Uses recorded in the sources include Propulsion distribution lines (tubing between components); Titanium metal parts for aerospace (all titanium metal, not CP grades alone).
Why it exists
Commercially pure (CP) titanium is unalloyed titanium sold as four ASTM grades, numbered 1 to 4. The grades differ mainly in strength: ATI prints a minimum yield strength of 138 MPa for grade 1 bar and billet, against 483 MPa for grade 4. CP titanium suits corrosion-resistant parts where strength is not the top requirement, and grade 2 tubing was used for the propulsion distribution lines of the China-Brazil CBERS satellite.
Where it's used
Satellite propulsion plumbing
Grade 2 commercially pure titanium tubing was specified as the distribution lines that connect the components of the CBERS satellite propulsion system (Orlowski de Garcia et al., 2010).
Aerospace
The USGS says the majority of titanium metal in 2025 was used in aerospace applications, with the rest going to armor, chemical processing, marine hardware, medical implants and power generation. This covers titanium metal in general, not the CP grades alone.
Recipe
Ti (unalloyed titanium, 99 to 99.5 % Ti overall). Composition maxima in weight % from the ATI tables: grade 1 Fe 0.20, O 0.18, C 0.08, N 0.03, H 0.015; grade 2 Fe 0.30, O 0.25, C 0.08, N 0.03, H 0.015; grade 3 Fe 0.30, O 0.35, C 0.08, N 0.03 to 0.05, H 0.015; grade 4 Fe 0.50, O 0.40, C 0.08, N 0.05, H 0.015; titanium balance in each grade
Commercially pure titanium is the element titanium, with small, limited amounts of oxygen, iron, carbon, nitrogen and hydrogen. Titanium metal is made by the Kroll process, which reduces titanium tetrachloride with magnesium (Wikipedia).
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Titanium Ti | balance | Main metal, which makes up the balance of each grade |
| Oxygen O | maximum, by grade (see identity formula) | Interstitial impurity; the paper says oxygen and nitrogen have a great effect on mechanical properties |
| Iron Fe | maximum, by grade (see identity formula) | Impurity with a lesser effect on mechanical properties than oxygen |
| Carbon C | maximum | Interstitial impurity; the composition table prints 0.08 max in all four grades |
| Nitrogen N | maximum, by grade (see identity formula) | Interstitial impurity, limited by grade and form |
| Hydrogen H | maximum 0.015 in all four grades | Interstitial impurity |
Weight shares are as printed in the sources.
What it can do
Strength
Grade 1 bar and billet have a minimum yield strength of 138 MPa, and grade 4 bar and billet have 483 MPa minimum (ATI).
Density
ATI prints 4.51 g/cm3 for each CP grade; the pure element is printed at 4.507 g/cm3 (periodictable.com).
Heat
The pure element melts at 1668 °C (periodictable.com). The ATI pages print no melting point for the CP grades.
Ductility
The minimum elongation falls from 24 % in grade 1 to 15 % in grade 4 (ATI).
How it compares
Across the four grades, a higher grade number buys strength at the cost of ductility: grade 1 has a minimum tensile strength of 240 MPa and 24 % elongation, while grade 4 has 550 MPa and 15 % (ATI). The Brazilian satellite welding paper says CP titanium welds well because it has low thermal conductivity and low linear thermal expansion. The record holds no comparison with other metals, so none is made here.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | CP Ti | CP Ti Grade 2 | Ti-6Al-4V | Ti-6Al-4V ELI | Ti-3Al-2.5V (Grade 9) | TiAl | Beta 3 | Ti Grade 11 | Ti Gr 12 | CP Ti Grade 3 | CP Ti Grade 7 | Ti minor alloys |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thermal behavior and safety | ||||||||||||
| Melting point, titanium element | 1668 °C18 | no data | 1604 °C | 1650 to 1660 °C | no data | no data | 3000 degF | 1670 °C | 1660 °C | no data | no data | 3000 degF |
| Thermal conductivity, titanium element | 21.9 W/(m·K)19 | 22 W/(m·K) | 6.7 W/(m K) | 6.6 W/(m K) | no data | no data | no data | 21.79 W/(m·K) | 19.02 W/(m·K) | 151.2 Btu-in/(hr·ft²·°F) | 21.79 W/m-K | 46.8 BTU-in/hr-ft2-°F |
| Specific heat capacity, titanium element | 520 J/(kg·K)24 | no data | 0.526 J/(g K) | 0.58 J/(g K) | no data | no data | no data | no data | 544 J/(kg·K) | no data | no data | no data |
| Physical and electrical | ||||||||||||
| Density, CP grade 1 | 4.51 g/cm³1 | 4.51 g/cm³ | 4.43 g/cm³ | 4.42 g/cm³ | 4.48 g/cm³ | 3.8 g/cm³ | 5.07 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.54 g/cm³ |
| Density, CP grade 2 (bar and billet) | 4.51 g/cm³2 | 4.51 g/cm³ | 4.43 g/cm³ | 4.42 g/cm³ | 4.48 g/cm³ | 3.8 g/cm³ | 5.07 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.54 g/cm³ |
| Density, CP grade 3 | 4.51 g/cm³3 | 4.51 g/cm³ | 4.43 g/cm³ | 4.42 g/cm³ | 4.48 g/cm³ | 3.8 g/cm³ | 5.07 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.54 g/cm³ |
| Density, CP grade 4 (bar and billet) | 4.51 g/cm³4 | 4.51 g/cm³ | 4.43 g/cm³ | 4.42 g/cm³ | 4.48 g/cm³ | 3.8 g/cm³ | 5.07 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.54 g/cm³ |
| Density, titanium element | 4.507 g/cm³17 | 4.51 g/cm³ | 4.43 g/cm³ | 4.42 g/cm³ | 4.48 g/cm³ | 3.8 g/cm³ | 5.07 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.51 g/cm³ | 4.54 g/cm³ |
| Other measurements | ||||||||||||
| Tensile strength minimum, CP grade 1 | > 240 MPa5 | > 345 MPa | no data | 828 MPa | > 620 MPa | 422 MPa | 1000 MPa | > 240 MPa | > 483 MPa | > 450 MPa | > 345 MPa | < 175 ksi |
| Tensile strength minimum, CP grade 2 | > 345 MPa6 | > 345 MPa | no data | 828 MPa | > 620 MPa | 422 MPa | 1000 MPa | > 240 MPa | > 483 MPa | > 450 MPa | > 345 MPa | < 175 ksi |
| Tensile strength minimum, CP grade 3 | > 450 MPa7 | > 345 MPa | no data | 828 MPa | > 620 MPa | 422 MPa | 1000 MPa | > 240 MPa | > 483 MPa | > 450 MPa | > 345 MPa | < 175 ksi |
| Tensile strength minimum, CP grade 4 | > 550 MPa8 | > 345 MPa | no data | 828 MPa | > 620 MPa | 422 MPa | 1000 MPa | > 240 MPa | > 483 MPa | > 450 MPa | > 345 MPa | < 175 ksi |
| Yield strength Rp0.2 minimum, CP grade 1 | > 138 MPa9 | > 275 MPa | 830 MPa | 759 MPa | > 483 MPa | 326 MPa | 965 MPa | > 138 MPa | > 345 MPa | > 380 MPa | > 275 MPa | < 186 ksi |
| Yield strength minimum, CP grade 2 (bar and billet) | > 275 MPa10 | > 275 MPa | 830 MPa | 759 MPa | > 483 MPa | 326 MPa | 965 MPa | > 138 MPa | > 345 MPa | > 380 MPa | > 275 MPa | < 186 ksi |
| Yield strength minimum, CP grade 3 (bar and billet) | > 380 MPa11 | > 275 MPa | 830 MPa | 759 MPa | > 483 MPa | 326 MPa | 965 MPa | > 138 MPa | > 345 MPa | > 380 MPa | > 275 MPa | < 186 ksi |
| Yield strength minimum, CP grade 4 (bar and billet) | > 483 MPa12 | > 275 MPa | 830 MPa | 759 MPa | > 483 MPa | 326 MPa | 965 MPa | > 138 MPa | > 345 MPa | > 380 MPa | > 275 MPa | < 186 ksi |
| Elongation minimum, CP grade 1 | > 24 %13 | > 20 % | 10 % | 10 % | > 15 % | 1.7 % | 7 % | > 24 % | > 18 % | > 18 % | > 20 % | < 10 % |
| Elongation minimum, CP grade 2 | > 20 %14 | > 20 % | 10 % | 10 % | > 15 % | 1.7 % | 7 % | > 24 % | > 18 % | > 18 % | > 20 % | < 10 % |
| Elongation minimum, CP grade 3 | > 18 %15 | > 20 % | 10 % | 10 % | > 15 % | 1.7 % | 7 % | > 24 % | > 18 % | > 18 % | > 20 % | < 10 % |
| Elongation minimum, CP grade 4 | > 15 %16 | > 20 % | 10 % | 10 % | > 15 % | 1.7 % | 7 % | > 24 % | > 18 % | > 18 % | > 20 % | < 10 % |
| Young's modulus, titanium element | 116 GPa20 | 103 GPa | 113.8 GPa | 107 to 122 GPa | 91 GPa | 168 GPa | 82 GPa | 112 GPa | 103 GPa | 103 GPa | 112 GPa | 15000 ksi |
| Bulk modulus, titanium element | 110 GPa21 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Shear (rigidity) modulus, titanium element | 44 GPa22 | no data | no data | 41 to 45 GPa | 44 GPa | no data | no data | 41 GPa | no data | no data | 41 GPa | no data |
| Poisson's ratio, titanium element | 0.32 -23 | no data | 0.342 dimensionless | no data | 0.3 - | no data | no data | no data | no data | no data | no data | no data |
Why choose it, and why not
Good for
- Corrosion-resistant tubing and plumbing where strength is not the highest requirement. The paper says CP grades serve applications where corrosion resistance and high ductility matter more than mechanical resistance.
- Welded parts. The paper cites good weldability from low thermal conductivity and low linear thermal expansion.
Watch out for
- Strength climbs with the grade number: 138 MPa minimum yield for grade 1, 483 MPa for grade 4 (ATI).
- Titanium burns in oxygen-enriched gas. Ignition is the failure mode to design against (NASA White Sands).
- Oxygen and nitrogen have a great influence on mechanical properties, so the composition limits matter (Orlowski de Garcia et al.).
Commercially pure titanium is the choice when corrosion resistance and ductility matter more than strength. Grade 1 is the most ductile and grade 4 the strongest, as ATI's minimum values show.
Used in space products
Space hardware whose maker names CP Ti, with the part it is used for.
| Product | Where it is used |
|---|---|
| Proba-VESA | Focal plane interconnecting structure; Instrument mounting feet / flexures; Titanium isolators (ESA page) |
| Proba-3 Coronagraph spacecraftESA / Airbus | OBA unit attachment fittings; Instrument support bipods (3) |
| CHEOPSESA | Fastening bolt; Commemorative plaques (2) |
| Arquimea satellite thermal blanketsArquimea | Plume impingement shielding; Plume impingement shield |
| Apollo Lunar Roving VehicleBoeing | Tread chevrons; Inner frame (MESH-1 prototype wheel; flight material not stated) |
| Apollo Lunar Module (LM)Grumman / NASA | Some brackets and fasteners (lunar module); Descent-stage hot-area structure; Base heat shield support structure; Engine compartment blast shield; Descent propellant tanks (x4, titanium); Ascent propellant tanks (x2, spherical titanium) |
| Apollo Command and Service ModuleNorth American Aviation | Helium tanks (2); Fuel tanks (2); Oxidizer tanks (2); Cryogenic hydrogen tanks; Launch escape tower (welded titanium truss); SPS propellant tanks (x4: fuel storage and sump, oxidizer storage and sump); SM RCS helium tanks (x4, one per quad); SM RCS propellant tanks (two fuel and two oxidizer per quad) |
| CuriosityNASA / JPL | Suspension tubes and arms to wheels |
| James Webb Space TelescopeNASA | Backplane fittings and interfaces |
| Lunar Reconnaissance Orbiter (LRO)NASA Goddard Space Flight Center | Propellant tanks (2); Instrument mounting flexures |
| Orion spacecraftNASA | Heat shield skeleton |
| Parker Solar ProbeNASA / Johns Hopkins APL | Titanium truss under the heat shield; Radiator tubes (x4 radiators) |
| PerseveranceNASA / JPL | Wheel spokes; Legs / suspension tubing; Sample tubes (43) |
| Saturn VNASA | Outboard engine fairings and stabilization fins; Control pressure nitrogen bottle (2,200 cubic in); Helium storage spheres on the thrust structure (x8, titanium); Launch escape tower |
| Viking landerNASA | Propellant tanks (2) |
| Falcon 9SpaceX | Grid fins, titanium version |
| Lunar Module Descent Engine (LMDE)TRW | Ablative-lined case to 16:1; Structural shield; Exit-plane stiffening ring |
| Rutherford engineRocket Lab | Printed engine components (general statement) |
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| UNS | R50250 (CP grade 1), R50400 (CP grade 2), R50550 (CP grade 3), R50700 (CP grade 4) |
| ASTM | B265 |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density, CP grade 1 | Value printed in a manufacturer product page (ATI) | grade CP grade 1 (UNS R50250)form all forms as printedunit in source 0.163 lb/in3 | — |
| 2 | Density, CP grade 2 (bar and billet) | Value printed in a manufacturer product page (ATI) | grade CP grade 2 (UNS R50400)form bar and billetunit in source 0.163 lb/in3 | The same ATI page prints 4.52 g/cm3 for plate, sheet and strip of grade 2. |
| 3 | Density, CP grade 3 | Value printed in a manufacturer product page (ATI) | grade CP grade 3 (UNS R50550)form all forms as printedunit in source 0.163 lb/in3 | — |
| 4 | Density, CP grade 4 (bar and billet) | Value printed in a manufacturer product page (ATI) | grade CP grade 4 (UNS R50700)form bar and billetunit in source 0.163 lb/in3 | The same ATI page prints 4.52 g/cm3 for plate and strip and 4.51 g/cm3 for sheet of grade 4. |
| 5 | Tensile strength minimum, CP grade 1 | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 1 (UNS R50250)form all forms as printedbasis minimumunit in source 35 min ksi | — |
| 6 | Tensile strength minimum, CP grade 2 | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 2 (UNS R50400)form bar, billet, plate, sheet and strip (same minimum in each)basis minimumunit in source 50 min ksi | — |
| 7 | Tensile strength minimum, CP grade 3 | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 3 (UNS R50550)form bar, billet, plate, sheet and strip (same minimum in each)basis minimumunit in source 65 min ksi | — |
| 8 | Tensile strength minimum, CP grade 4 | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 4 (UNS R50700)form bar, billet, plate, sheet and strip (same minimum in each)basis minimumunit in source 80 min ksi | — |
| 9 | Yield strength Rp0.2 minimum, CP grade 1 | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 1 (UNS R50250)form bar, billet and platebasis minimumunit in source 20 min ksi | The same ATI page prints 138 min to 310 max MPa for sheet and strip of grade 1. |
| 10 | Yield strength minimum, CP grade 2 (bar and billet) | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 2 (UNS R50400)form bar and billetbasis minimumunit in source 40 min ksi | The same ATI page prints 275 min to 450 max MPa for plate, sheet and strip of grade 2. |
| 11 | Yield strength minimum, CP grade 3 (bar and billet) | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 3 (UNS R50550)form bar and billetbasis minimumunit in source 55 min ksi | The same ATI page prints 380 min to 550 max MPa for plate, sheet and strip of grade 3. |
| 12 | Yield strength minimum, CP grade 4 (bar and billet) | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 4 (UNS R50700)form bar and billetbasis minimumunit in source 70 min ksi | The same ATI page prints 483 min to 655 max MPa for plate and strip of grade 4. |
| 13 | Elongation minimum, CP grade 1 | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 1 (UNS R50250)form all forms as printedbasis minimum | — |
| 14 | Elongation minimum, CP grade 2 | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 2 (UNS R50400)form bar, billet, plate, sheet and stripbasis minimum | — |
| 15 | Elongation minimum, CP grade 3 | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 3 (UNS R50550)form bar, billet, plate, sheet and stripbasis minimum | — |
| 16 | Elongation minimum, CP grade 4 | Minimum value printed in a manufacturer product page (ATI) | grade CP grade 4 (UNS R50700)form bar, billet, plate and stripbasis minimum | — |
| 17 | Density, titanium element | Value printed on a periodic-table data page for the element | form pure element titaniumtemperature not stated on the page | — |
| 18 | Melting point, titanium element | Value printed on a periodic-table data page for the element | form pure element titaniumpressure not stated on the page | The ATI pages for the CP grades print no melting point. |
| 19 | Thermal conductivity, titanium element | Value printed on a WebElements physical properties page | form pure element titaniumtemperature not stated on the pageunit in source W m-1 K-1 | The periodic-table data page prints 22 W/(m K) for the same property, which rounds this figure. |
| 20 | Young's modulus, titanium element | Value printed on a WebElements physical properties page | form pure element titaniumtemperature not stated on the page | — |
| 21 | Bulk modulus, titanium element | Value printed on a WebElements physical properties page | form pure element titaniumtemperature not stated on the page | — |
| 22 | Shear (rigidity) modulus, titanium element | Value printed on a WebElements physical properties page, named rigidity modulus | form pure element titaniumtemperature not stated on the page | — |
| 23 | Poisson's ratio, titanium element | Value printed on a WebElements physical properties page | form pure element titaniumunit in source no units printed | — |
| 24 | Specific heat capacity, titanium element | Value printed on a periodic-table data page for the element | form solid phase, pure element titanium | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Oxidizing acids and air (passive oxide film) | low | A thin passive oxide layer protects titanium against oxidizing acids.1 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Oxidizing acids and air (passive oxide film) | Wikipedia describes a thin, non-porous passivation layer that protects the bulk metal from further oxidation or corrosion, and says this layer gives titanium excellent resistance to corrosion against oxidizing acids. The page gives no rate. | basis qualitative statement in an encyclopedia article, no test conditions printed |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The GHS record for elemental titanium is mostly 'not classified', but some company notifications carry hazard codes.
- Classification
- PubChem records 606 of 808 company reports as not meeting GHS hazard criteria, and 202 of 808 reports with hazard statement codes (ECHA C&L Inventory aggregate).
- Hazard codes
- The codes given are H228 flammable solid, H250 catches fire spontaneously if exposed to air, and H251 self-heating, with signal word Danger.
- Impurities
- PubChem says the classification may vary with impurities, additives and other factors.
Ignition and burning
NASA's White Sands test facility measured how CP grade 2 rods burn in oxygen-enriched gas (Stoltzfus et al., 2012).
- Test gas
- Rods were ignited at the bottom and burned upward in 70 % O2 balance N2 and in 99.5+% O2 at several pressures.
- Diameter
- The burning rate increased as diameter decreased, and it increased with test gas pressure and oxygen concentration.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Ignition and burning in oxygen-enriched gashigh severity | Rods of CP grade 2 ignited at the bottom and burned upward in 70 % O2 balance N2 and in 99.5+% O2 at several pressures (NASA White Sands test)The burning rate increased as rod diameter decreased, and increased with test gas pressure and oxygen concentration. The authors ran this test to support a failure analysis. |
| Oxygen and nitrogen change strength and ductilitymoderate severity | Interstitial oxygen and nitrogen above the grade's composition limits (ATI tables)The paper says oxygen and nitrogen exert a great extent of influence on mechanical properties, while iron and carbon have a lesser impact. |
Handling and storage
- Specify the grade and its composition limits, because oxygen and nitrogen exert a great extent of influence on mechanical properties (Orlowski de Garcia et al.).
- Keep titanium away from oxygen-enriched gas and ignition sources. The NASA White Sands paper states that titanium and its alloys are easily ignited and burn vigorously in oxygen-enriched atmospheres.
- For welded propulsion lines, the CBERS team worked in a clean room with controlled humidity, temperature and particulates (Orlowski de Garcia et al.).
Supply and geography
How common the raw materials are and where they come from.
Titanium sponge metal (feedstock for mill products, including CP grades)
Titanium is the ninth-most abundant element in Earth's crust, at 0.63 % by mass (Wikipedia).
- Top producers (2025)
- China 70.3%, Japan 14.3%, Russia 6.8%, Kazakhstan 4.3%, Saudi Arabia 3.2%
- Recycling
- USGS: U.S. imports of titanium scrap were estimated at 32,000 tons in 2025, and consumption data for titanium scrap in the titanium metal industry were withheld. A company in Virginia began titanium powder production from scrap in late 2024.
- Substitutes
- USGS: aluminum, nickel, specialty steels and zirconium alloys may be substituted for titanium where corrosion resistance is required.
Titanium ore feedstock (rutile or ilmenite for the Kroll process)
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
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spore: profile
id: titanium
spore_version: '0.2'
family: titanium-alloys
name: Titanium (commercially pure, grades 1 to 4)
abbreviation: CP Ti
role: unalloyed corrosion-resistant metal for tubing and plumbing
category: metals
type: titanium
summary: |
Commercially pure titanium is unalloyed titanium sold as ASTM grades 1 to 4, which differ in their limits on oxygen, iron, carbon, nitrogen and hydrogen. ATI prints a density of 4.51 g/cm3 for each grade, and a minimum yield strength of 138 MPa for grade 1 against 483 MPa for grade 4 in bar and billet. NASA's White Sands test facility tested grade 2 rods and found that they burn in oxygen-enriched gas.
best_for: Corrosion-resistant tubing and plumbing where strength is secondary; grade 1 is the most ductile (ATI minimum elongation 24 %)
weakest_at: Strength in the lower grades (grade 1 has a 138 MPa minimum yield strength, ATI), and ignition in oxygen-enriched gas (NASA)
identity:
formula: 'Ti (unalloyed titanium, 99 to 99.5 % Ti overall). Composition maxima in weight % from the ATI tables: grade 1 Fe 0.20, O 0.18, C 0.08, N 0.03, H 0.015; grade 2 Fe 0.30, O 0.25, C 0.08, N 0.03, H 0.015; grade 3 Fe 0.30, O 0.35, C 0.08, N 0.03 to 0.05, H 0.015; grade 4 Fe 0.50, O 0.40, C 0.08, N 0.05, H 0.015; titanium balance in each grade'
source: ati-cp1
where: Composition tables of the ATI CP grade 1 to 4 pages (maxima, Ti balance). The 99 to 99.5 % Ti overall range is from the Orlowski de Garcia et al. paper (redalyc-cbers).
designations:
- system: UNS
code: R50250
note: CP grade 1
source: ati-cp1
where: Designations block, UNS line
- system: UNS
code: R50400
note: CP grade 2
source: ati-cp2
where: Designations block, UNS line
- system: UNS
code: R50550
note: CP grade 3
source: ati-cp3
where: Designations block, title line ATI 55 CP Grade 3
- system: UNS
code: R50700
note: CP grade 4
source: ati-cp4
where: Designations block, UNS line
- system: ASTM
code: B265
source: ati-cp1
where: Designations block, Bar and Billet specifications line
tags:
environments: []
stresses: []
applications:
- propulsion-and-tanks
- structures
properties:
- benchmark: density
label: Density, CP grade 1
value: 4.51
unit: g/cm3
scope: material
conditions:
grade: CP grade 1 (UNS R50250)
form: all forms as printed
unit_in_source: 0.163 lb/in3
method: Value printed in a manufacturer product page (ATI)
status: ground
source: ati-cp1
where: Density row, all forms
- benchmark: density
label: Density, CP grade 2 (bar and billet)
value: 4.51
unit: g/cm3
scope: material
conditions:
grade: CP grade 2 (UNS R50400)
form: bar and billet
unit_in_source: 0.163 lb/in3
method: Value printed in a manufacturer product page (ATI)
status: ground
note: The same ATI page prints 4.52 g/cm3 for plate, sheet and strip of grade 2.
source: ati-cp2
where: Density row, Bar and Billet section
- benchmark: density
label: Density, CP grade 3
value: 4.51
unit: g/cm3
scope: material
conditions:
grade: CP grade 3 (UNS R50550)
form: all forms as printed
unit_in_source: 0.163 lb/in3
method: Value printed in a manufacturer product page (ATI)
status: ground
source: ati-cp3
where: Density row, Bar and Billet and Plate, Sheet and Strip sections
- benchmark: density
label: Density, CP grade 4 (bar and billet)
value: 4.51
unit: g/cm3
scope: material
conditions:
grade: CP grade 4 (UNS R50700)
form: bar and billet
unit_in_source: 0.163 lb/in3
method: Value printed in a manufacturer product page (ATI)
status: ground
note: The same ATI page prints 4.52 g/cm3 for plate and strip and 4.51 g/cm3 for sheet of grade 4.
source: ati-cp4
where: Density row, Bar and Billet section
- benchmark: ultimate_tensile_strength
label: Tensile strength minimum, CP grade 1
value: 240
bound: lower
unit: MPa
scope: material
conditions:
grade: CP grade 1 (UNS R50250)
form: all forms as printed
basis: minimum
unit_in_source: 35 min ksi
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
source: ati-cp1
where: Tensile Strength row, all forms, MPa column
- benchmark: ultimate_tensile_strength
label: Tensile strength minimum, CP grade 2
value: 345
bound: lower
unit: MPa
scope: material
conditions:
grade: CP grade 2 (UNS R50400)
form: bar, billet, plate, sheet and strip (same minimum in each)
basis: minimum
unit_in_source: 50 min ksi
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
source: ati-cp2
where: Tensile Strength row, Bar and Billet and Plate sections, MPa column
- benchmark: ultimate_tensile_strength
label: Tensile strength minimum, CP grade 3
value: 450
bound: lower
unit: MPa
scope: material
conditions:
grade: CP grade 3 (UNS R50550)
form: bar, billet, plate, sheet and strip (same minimum in each)
basis: minimum
unit_in_source: 65 min ksi
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
source: ati-cp3
where: Tensile Strength row, MPa column
- benchmark: ultimate_tensile_strength
label: Tensile strength minimum, CP grade 4
value: 550
bound: lower
unit: MPa
scope: material
conditions:
grade: CP grade 4 (UNS R50700)
form: bar, billet, plate, sheet and strip (same minimum in each)
basis: minimum
unit_in_source: 80 min ksi
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
source: ati-cp4
where: Tensile Strength row, MPa column
- benchmark: yield_strength
label: Yield strength Rp0.2 minimum, CP grade 1
value: 138
bound: lower
unit: MPa
scope: material
conditions:
grade: CP grade 1 (UNS R50250)
form: bar, billet and plate
basis: minimum
unit_in_source: 20 min ksi
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
note: The same ATI page prints 138 min to 310 max MPa for sheet and strip of grade 1.
source: ati-cp1
where: Yield Strength row, Bar, Billet, Plate section, MPa column
- benchmark: yield_strength
label: Yield strength minimum, CP grade 2 (bar and billet)
value: 275
bound: lower
unit: MPa
scope: material
conditions:
grade: CP grade 2 (UNS R50400)
form: bar and billet
basis: minimum
unit_in_source: 40 min ksi
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
note: The same ATI page prints 275 min to 450 max MPa for plate, sheet and strip of grade 2.
source: ati-cp2
where: Yield Strength row, Bar and Billet section, MPa column
- benchmark: yield_strength
label: Yield strength minimum, CP grade 3 (bar and billet)
value: 380
bound: lower
unit: MPa
scope: material
conditions:
grade: CP grade 3 (UNS R50550)
form: bar and billet
basis: minimum
unit_in_source: 55 min ksi
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
note: The same ATI page prints 380 min to 550 max MPa for plate, sheet and strip of grade 3.
source: ati-cp3
where: Yield Strength row, Bar and Billet section, MPa column
- benchmark: yield_strength
label: Yield strength minimum, CP grade 4 (bar and billet)
value: 483
bound: lower
unit: MPa
scope: material
conditions:
grade: CP grade 4 (UNS R50700)
form: bar and billet
basis: minimum
unit_in_source: 70 min ksi
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
note: The same ATI page prints 483 min to 655 max MPa for plate and strip of grade 4.
source: ati-cp4
where: Yield Strength row, Bar and Billet section, MPa column
- benchmark: elongation
label: Elongation minimum, CP grade 1
value: 24
bound: lower
unit: '%'
scope: material
conditions:
grade: CP grade 1 (UNS R50250)
form: all forms as printed
basis: minimum
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
source: ati-cp1
where: Elongation row, all forms
- benchmark: elongation
label: Elongation minimum, CP grade 2
value: 20
bound: lower
unit: '%'
scope: material
conditions:
grade: CP grade 2 (UNS R50400)
form: bar, billet, plate, sheet and strip
basis: minimum
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
source: ati-cp2
where: Elongation row, Bar and Billet and Plate, Sheet and Strip sections
- benchmark: elongation
label: Elongation minimum, CP grade 3
value: 18
bound: lower
unit: '%'
scope: material
conditions:
grade: CP grade 3 (UNS R50550)
form: bar, billet, plate, sheet and strip
basis: minimum
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
source: ati-cp3
where: Elongation row, Bar and Plate sections
- benchmark: elongation
label: Elongation minimum, CP grade 4
value: 15
bound: lower
unit: '%'
scope: material
conditions:
grade: CP grade 4 (UNS R50700)
form: bar, billet, plate and strip
basis: minimum
method: Minimum value printed in a manufacturer product page (ATI)
status: ground
source: ati-cp4
where: Elongation row, Bar and Billet and Plate, Sheet and Strip sections
- benchmark: density
label: Density, titanium element
value: 4.507
unit: g/cm3
scope: material
conditions:
form: pure element titanium
temperature: not stated on the page
method: Value printed on a periodic-table data page for the element
status: ground
source: periodictable-ti
where: Overview and Bulk physical properties sections
- benchmark: melting_point
label: Melting point, titanium element
value: 1668
unit: °C
scope: material
conditions:
form: pure element titanium
pressure: not stated on the page
method: Value printed on a periodic-table data page for the element
status: ground
note: The ATI pages for the CP grades print no melting point.
source: periodictable-ti
where: Overview and Thermal properties sections
- benchmark: thermal_conductivity
label: Thermal conductivity, titanium element
value: 21.9
unit: W/(m·K)
scope: material
conditions:
form: pure element titanium
temperature: not stated on the page
unit_in_source: W m-1 K-1
method: Value printed on a WebElements physical properties page
status: ground
note: The periodic-table data page prints 22 W/(m K) for the same property, which rounds this figure.
source: webelements-ti
where: Heat and conduction section, Thermal conductivity
- benchmark: elastic_modulus
label: Young's modulus, titanium element
value: 116
unit: GPa
scope: material
conditions:
form: pure element titanium
temperature: not stated on the page
method: Value printed on a WebElements physical properties page
status: ground
source: webelements-ti
where: Elastic properties section, Young's modulus
- benchmark: bulk_modulus
label: Bulk modulus, titanium element
value: 110
unit: GPa
scope: material
conditions:
form: pure element titanium
temperature: not stated on the page
method: Value printed on a WebElements physical properties page
status: ground
source: webelements-ti
where: Elastic properties section, Bulk modulus
- benchmark: shear_modulus
label: Shear (rigidity) modulus, titanium element
value: 44
unit: GPa
scope: material
conditions:
form: pure element titanium
temperature: not stated on the page
method: Value printed on a WebElements physical properties page, named rigidity modulus
status: ground
source: webelements-ti
where: Elastic properties section, Rigidity modulus
- benchmark: poissons_ratio
label: Poisson's ratio, titanium element
value: 0.32
unit: '-'
scope: material
conditions:
form: pure element titanium
unit_in_source: no units printed
method: Value printed on a WebElements physical properties page
status: ground
source: webelements-ti
where: Elastic properties section, Poisson's ratio
- benchmark: specific_heat
label: Specific heat capacity, titanium element
value: 520
unit: J/(kg·K)
scope: material
conditions:
form: solid phase, pure element titanium
method: Value printed on a periodic-table data page for the element
status: ground
source: periodictable-ti
where: Thermal properties section, Specific heat
corrosion:
- environment: Oxidizing acids and air (passive oxide film)
headline: A thin passive oxide layer protects titanium against oxidizing acids.
effect: Wikipedia describes a thin, non-porous passivation layer that protects the bulk metal from further oxidation or corrosion, and says this layer gives titanium excellent resistance to corrosion against oxidizing acids. The page gives no rate.
rating: low
conditions:
basis: qualitative statement in an encyclopedia article, no test conditions printed
source: wikipedia-ti
where: Passivation and corrosion-resistance paragraph
risks:
hazards:
- text: 'PubChem''s aggregate of ECHA C&L Inventory notifications for titanium: 606 of 808 company reports say the substance does not meet GHS hazard criteria, and 202 of 808 reports give hazard statement codes. The signal word given is Danger. The record says the classification may vary with impurities, additives and other factors.'
ghs:
- H228
- H250
- H251
source: pubchem-ti
where: GHS Classification section of the PubChem record for titanium, CID 23963
failure_risks:
- mode: Ignition and burning in oxygen-enriched gas
trigger: Rods of CP grade 2 ignited at the bottom and burned upward in 70 % O2 balance N2 and in 99.5+% O2 at several pressures (NASA White Sands test)
consequence: The burning rate increased as rod diameter decreased, and increased with test gas pressure and oxygen concentration. The authors ran this test to support a failure analysis.
severity: high
source: nasa-wstf-ti-flam
where: Abstract and Background; Test Samples section (CP titanium Grade 2, UNS R50400)
- mode: Oxygen and nitrogen change strength and ductility
trigger: Interstitial oxygen and nitrogen above the grade's composition limits (ATI tables)
consequence: The paper says oxygen and nitrogen exert a great extent of influence on mechanical properties, while iron and carbon have a lesser impact.
severity: moderate
source: redalyc-cbers
where: Introduction, paragraph on commercially pure titanium composition
side_effects: []
handling:
- text: Specify the grade and its composition limits, because oxygen and nitrogen exert a great extent of influence on mechanical properties (Orlowski de Garcia et al.).
source: redalyc-cbers
where: Introduction, paragraph on commercially pure titanium composition
- text: Keep titanium away from oxygen-enriched gas and ignition sources. The NASA White Sands paper states that titanium and its alloys are easily ignited and burn vigorously in oxygen-enriched atmospheres.
source: nasa-wstf-ti-flam
where: Background section
- text: For welded propulsion lines, the CBERS team worked in a clean room with controlled humidity, temperature and particulates (Orlowski de Garcia et al.).
source: redalyc-cbers
where: Materials and Methods, first paragraphs
mitigations: []
uses:
- application: propulsion-and-tanks
device: Propulsion distribution lines (tubing between components)
example: Grade 2 commercially pure titanium tubing was specified as the distribution lines that interconnect the components of the China-Brazil CBERS satellite propulsion system, which includes four hydrazine fuel tanks, thrusters and valves.
source: redalyc-cbers
where: Introduction, first two paragraphs
- application: structures
device: Titanium metal parts for aerospace (all titanium metal, not CP grades alone)
example: The USGS says the majority of titanium metal was used in aerospace applications in 2025, although detailed consumption data were withheld.
source: usgs-mcs2026-titanium
where: Domestic Production and Use paragraph
supply:
- subject: Titanium sponge metal (feedstock for mill products, including CP grades)
abundance: Titanium is the ninth-most abundant element in Earth's crust, at 0.63 % by mass (Wikipedia).
producers:
- country: China
share_percent: 70.3
year: 2025
- country: Japan
share_percent: 14.3
year: 2025
- country: Russia
share_percent: 6.8
year: 2025
- country: Kazakhstan
share_percent: 4.3
year: 2025
- country: Saudi Arabia
share_percent: 3.2
year: 2025
critical_lists: []
recycling: 'USGS: U.S. imports of titanium scrap were estimated at 32,000 tons in 2025, and consumption data for titanium scrap in the titanium metal industry were withheld. A company in Virginia began titanium powder production from scrap in late 2024.'
substitutes:
- 'USGS: aluminum, nickel, specialty steels and zirconium alloys may be substituted for titanium where corrosion resistance is required.'
source: usgs-mcs2026-titanium
where: 'World Sponge Metal Production table, 2025e column (metric tons: China 260,000; Japan 53,000; Russia 25,000; Kazakhstan 16,000; Saudi Arabia 12,000; world total 370,000). Shares are country value divided by 370,000, calculated by Space Mushroom. Also the Recycling, Substitutes and Events, Trends, and Issues sections.'
- subject: Titanium ore feedstock (rutile or ilmenite for the Kroll process)
producers: []
critical_lists: []
substitutes: []
source: wikipedia-ti
where: Production paragraph (Kroll process) and its feedstock sentence
documents:
- title: ATI 30, CP Grade 1 Titanium product page
type: datasheet
url: https://www.atimaterials.com/Products/ati-cp1
- title: ATI CP Grade 2 Titanium product page
type: datasheet
url: https://www.atimaterials.com/Products/ati-cp2
- title: ATI 55, CP Grade 3 Titanium product page
type: datasheet
url: https://www.atimaterials.com/Products/ati-cp3
- title: ATI 70, CP Grade 4 Titanium product page
type: datasheet
url: https://www.atimaterials.com/Products/ati-cp4
- title: 'WebElements: Titanium physical properties'
type: database
url: https://www.webelements.com/titanium/physics.html
- title: 'Periodic Table: Titanium element data'
type: database
url: https://periodictable.com/Elements/022/data.html
- title: 'USGS Mineral Commodity Summaries 2026: Titanium and Titanium Dioxide'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf
year: 2026
- title: PubChem compound record for titanium, CID 23963 (GHS classification)
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/23963
- title: 'Wikipedia: Titanium'
type: database
url: https://en.wikipedia.org/wiki/Titanium
- title: Orlowski de Garcia et al., Advances of orbital gas tungsten arc welding for Brazilian space applications, Journal of Aerospace Technology and Management, 2010
type: paper
url: https://www.redalyc.org/pdf/3094/309426553009.pdf
year: 2010
- title: Stoltzfus, Jeffers and Gallus, Burning of CP Titanium (Grade 2) in Oxygen-Enriched Atmospheres, ASTM International, 2012
type: paper
url: https://ntrs.nasa.gov/citations/20120002982
year: 2012
gaps:
- Melting point, thermal conductivity and elastic modulus for each CP grade were not printed on the ATI pages. The values recorded are for the pure element, from WebElements and periodictable.com.
- Coefficient of thermal expansion and electrical resistivity are printed in exponent notation on WebElements and periodictable.com, so they are left out under the exponent rule.
- Hardness, fatigue strength, fracture toughness and creep for the CP grades were not read in this run.
- Seawater and chloride corrosion rates for the CP grades were not read in this run. The titanium grade 2 profile covers the grade 2 datasheets for that environment.
- The titanium critical-mineral list status was not in the USGS 2026 text we read, so critical_lists is empty.
- PubChem's hazard percentages were not captured. The counts of 606 of 808 and 202 of 808 reports are recorded instead.
- Radiation, atomic oxygen and vacuum outgassing data for titanium were not looked up.
- Recycling rates for titanium scrap were not found. USGS withheld the consumption data.
- Space uses of CP grades beyond the CBERS propulsion distribution lines were not found. The USGS use text covers titanium metal in general, not CP grades alone.
- Composition limits are recorded in identity.formula and the recipe, not as property rows.
sources:
ati-cp1:
title: ATI 30, CP Grade 1 Titanium product page (ATI Materials)
url: https://www.atimaterials.com/Products/ati-cp1
kind: datasheet
ati-cp2:
title: ATI CP Grade 2 Titanium product page (ATI Materials)
url: https://www.atimaterials.com/Products/ati-cp2
kind: datasheet
ati-cp3:
title: ATI 55, CP Grade 3 Titanium product page (ATI Materials)
url: https://www.atimaterials.com/Products/ati-cp3
kind: datasheet
ati-cp4:
title: ATI 70, CP Grade 4 Titanium product page (ATI Materials)
url: https://www.atimaterials.com/Products/ati-cp4
kind: datasheet
webelements-ti:
title: 'WebElements: Titanium physical properties'
url: https://www.webelements.com/titanium/physics.html
kind: database
periodictable-ti:
title: 'Periodic Table: Titanium element data'
url: https://periodictable.com/Elements/022/data.html
kind: database
usgs-mcs2026-titanium:
title: 'USGS Mineral Commodity Summaries 2026: Titanium and Titanium Dioxide'
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf
year: 2026
kind: report
pubchem-ti:
title: PubChem compound record for titanium, CID 23963
url: https://pubchem.ncbi.nlm.nih.gov/compound/23963
kind: database
wikipedia-ti:
title: 'Wikipedia: Titanium'
url: https://en.wikipedia.org/wiki/Titanium
kind: web
license: CC BY-SA 4.0 (cited, not reproduced)
redalyc-cbers:
title: Orlowski de Garcia et al., Advances of orbital gas tungsten arc welding for Brazilian space applications - experimental setup, Journal of Aerospace Technology and Management 2(2), 2010
url: https://www.redalyc.org/pdf/3094/309426553009.pdf
year: 2010
kind: paper
nasa-wstf-ti-flam:
title: Stoltzfus, Jeffers and Gallus, Burning of CP Titanium (Grade 2) in Oxygen-Enriched Atmospheres, Journal of ASTM International (NASA JSC-CN-25709)
url: https://ntrs.nasa.gov/citations/20120002982
year: 2012
kind: paper
license: CC-BY-4.0
updated: '2026-11-01'
review:
status: draft
method: assistant
checked_values: 24
unreachable: 0
caveats: 0
note: Written by an AI assistant on 2026-11-01 from the cited pages. Values were copied from the fetched pages; see gaps for what was not found.
story:
recipe:
line: Commercially pure titanium is the element titanium, with small, limited amounts of oxygen, iron, carbon, nitrogen and hydrogen. Titanium metal is made by the Kroll process, which reduces titanium tetrachloride with magnesium (Wikipedia).
parts:
- name: Titanium
symbol: Ti
role: Main metal, which makes up the balance of each grade
share_note: balance
source: ati-cp1
where: Composition table, Ti row
- name: Oxygen
symbol: O
role: Interstitial impurity; the paper says oxygen and nitrogen have a great effect on mechanical properties
share_note: maximum, by grade (see identity formula)
source: ati-cp4
where: Composition table, O row
- name: Iron
symbol: Fe
role: Impurity with a lesser effect on mechanical properties than oxygen
share_note: maximum, by grade (see identity formula)
source: ati-cp1
where: Composition table, Fe row
- name: Carbon
symbol: C
role: Interstitial impurity; the composition table prints 0.08 max in all four grades
share_note: maximum
source: ati-cp1
where: Composition table, C row
- name: Nitrogen
symbol: 'N'
role: Interstitial impurity, limited by grade and form
share_note: maximum, by grade (see identity formula)
source: ati-cp3
where: Composition table, N row
- name: Hydrogen
symbol: H
role: Interstitial impurity
share_note: maximum 0.015 in all four grades
source: ati-cp1
where: Composition table, H row
risk_groups:
- title: For people
lead: The GHS record for elemental titanium is mostly 'not classified', but some company notifications carry hazard codes.
points:
- label: Classification
line: PubChem records 606 of 808 company reports as not meeting GHS hazard criteria, and 202 of 808 reports with hazard statement codes (ECHA C&L Inventory aggregate).
- label: Hazard codes
line: The codes given are H228 flammable solid, H250 catches fire spontaneously if exposed to air, and H251 self-heating, with signal word Danger.
- label: Impurities
line: PubChem says the classification may vary with impurities, additives and other factors.
level: 2
verdict: Mostly not classified
- title: Ignition and burning
lead: NASA's White Sands test facility measured how CP grade 2 rods burn in oxygen-enriched gas (Stoltzfus et al., 2012).
points:
- label: Test gas
line: Rods were ignited at the bottom and burned upward in 70 % O2 balance N2 and in 99.5+% O2 at several pressures.
- label: Diameter
line: The burning rate increased as diameter decreased, and it increased with test gas pressure and oxygen concentration.
level: 3
verdict: Burns in oxygen-enriched gas
why: 'Commercially pure (CP) titanium is unalloyed titanium sold as four ASTM grades, numbered 1 to 4. The grades differ mainly in strength: ATI prints a minimum yield strength of 138 MPa for grade 1 bar and billet, against 483 MPa for grade 4. CP titanium suits corrosion-resistant parts where strength is not the top requirement, and grade 2 tubing was used for the propulsion distribution lines of the China-Brazil CBERS satellite.'
uses:
- where: Satellite propulsion plumbing
line: Grade 2 commercially pure titanium tubing was specified as the distribution lines that connect the components of the CBERS satellite propulsion system (Orlowski de Garcia et al., 2010).
- where: Aerospace
line: The USGS says the majority of titanium metal in 2025 was used in aerospace applications, with the rest going to armor, chemical processing, marine hardware, medical implants and power generation. This covers titanium metal in general, not the CP grades alone.
can_do:
- label: Strength
line: Grade 1 bar and billet have a minimum yield strength of 138 MPa, and grade 4 bar and billet have 483 MPa minimum (ATI).
- label: Density
line: ATI prints 4.51 g/cm3 for each CP grade; the pure element is printed at 4.507 g/cm3 (periodictable.com).
- label: Heat
line: The pure element melts at 1668 °C (periodictable.com). The ATI pages print no melting point for the CP grades.
- label: Ductility
line: The minimum elongation falls from 24 % in grade 1 to 15 % in grade 4 (ATI).
compare: 'Across the four grades, a higher grade number buys strength at the cost of ductility: grade 1 has a minimum tensile strength of 240 MPa and 24 % elongation, while grade 4 has 550 MPa and 15 % (ATI). The Brazilian satellite welding paper says CP titanium welds well because it has low thermal conductivity and low linear thermal expansion. The record holds no comparison with other metals, so none is made here.'
compare_rows:
- label: Yield strength, minimum, bar and billet
benchmark: yield_strength
- label: Tensile strength, minimum
benchmark: ultimate_tensile_strength
- label: Density
benchmark: density
handling:
- Oxygen and nitrogen strongly affect the properties, so buy to the grade's composition limits (Orlowski de Garcia et al.).
- Keep titanium away from oxygen-enriched gas and ignition sources. The NASA paper says titanium and its alloys are easily ignited and burn vigorously in oxygen-enriched atmospheres.
- For welded propulsion lines, the CBERS team worked in a clean room with controlled humidity, temperature and particulates.
good_for:
- Corrosion-resistant tubing and plumbing where strength is not the highest requirement. The paper says CP grades serve applications where corrosion resistance and high ductility matter more than mechanical resistance.
- Welded parts. The paper cites good weldability from low thermal conductivity and low linear thermal expansion.
watch_out:
- 'Strength climbs with the grade number: 138 MPa minimum yield for grade 1, 483 MPa for grade 4 (ATI).'
- Titanium burns in oxygen-enriched gas. Ignition is the failure mode to design against (NASA White Sands).
- Oxygen and nitrogen have a great influence on mechanical properties, so the composition limits matter (Orlowski de Garcia et al.).
verdict: Commercially pure titanium is the choice when corrosion resistance and ductility matter more than strength. Grade 1 is the most ductile and grade 4 the strongest, as ATI's minimum values show.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| ATI 30, CP Grade 1 Titanium product page (ATI Materials) | datasheet | 5 values | ||
| ATI CP Grade 2 Titanium product page (ATI Materials) | datasheet | 4 values | ||
| ATI 55, CP Grade 3 Titanium product page (ATI Materials) | datasheet | 4 values | ||
| ATI 70, CP Grade 4 Titanium product page (ATI Materials) | datasheet | 4 values | ||
| WebElements: Titanium physical properties | database | 5 values | ||
| Periodic Table: Titanium element data | database | 3 values | ||
| USGS Mineral Commodity Summaries 2026: Titanium and Titanium Dioxide | report | 2026 | 2 values | |
| PubChem compound record for titanium, CID 23963 | database | 1 value | ||
| Wikipedia: Titanium | web | 2 values | ||
| Orlowski de Garcia et al., Advances of orbital gas tungsten arc welding for Brazilian space applications - experimental setup, Journal of Aerospace Technology and Management 2(2), 2010 | paper | 2010 | 4 values | |
| Stoltzfus, Jeffers and Gallus, Burning of CP Titanium (Grade 2) in Oxygen-Enriched Atmospheres, Journal of ASTM International (NASA JSC-CN-25709) | paper | 2012 | 2 values |
Updated