spore: profile
id: titanium-grade-2
spore_version: 0.2
family: titanium-alloys
name: Commercially pure titanium, Grade 2 (UNS R50400)
abbreviation: CP Ti Grade 2
role: corrosion-resistant unalloyed metal
category: metals
type: titanium
summary: |
  Commercially pure (CP) titanium Grade 2, UNS R50400, is unalloyed titanium with low limits on oxygen, iron, carbon, nitrogen and hydrogen. The Smiths datasheet calls it the most frequently employed unalloyed titanium grade. ASTM B265 sets its minimum tensile strength at 345 MPa and its minimum 0.2 % yield strength at 275 MPa, with 20 % minimum elongation for sheet and plate. The Alleima tube datasheet gives a density of 4.51 g/cm3 and an elastic modulus of 103 GPa in tension. Its main strength is seawater and chloride resistance, but one test found Grade 2 crevice-corroded at 80 °C in near-anaerobic seawater.
best_for: Seawater, brine and chloride service where corrosion resistance and formability matter more than strength (Alleima and Smiths datasheets)
weakest_at: 'Strength: 345 MPa minimum tensile, well below Ti-6Al-4V (see the Ti-6Al-4V profile). Crevice attack in hot seawater from about 80 °C (Pang and Blackwood 2016)'
identity:
  formula: 'Unalloyed titanium, UNS R50400 (ASTM Grade 2): maximum limits on O, Fe, C, N and H, titanium the balance'
  cas: 7440-32-6
  source: astm-b265
  where: Table 2 Chemical Requirements, Grade 2 column (ASTM B265-08b copy); CAS from PubChem CID 23963 (pubchem-ti)
  designations:
    - system: UNS
      code: R50400
      source: smith-cp2
      where: Material Specifications list, UNS R50400 line
    - system: Name
      code: Titanium Grade 2
      source: austral-wright
      where: Product data sheet heading, Titanium Grade 2 UNS-R50400
    - system: Trade name
      code: Ti Grade 2
      source: alleima-ti2
      where: Datasheet title, Alleima Ti Grade 2
    - system: ASTM
      code: B265
      note: strip, sheet and plate
      source: astm-b265
      where: Title, designation B 265 - 08b; Table 2 Chemical Requirements, Grade 2 column
    - system: ASTM
      code: B348
      note: bars and billets
      source: smith-cp2
      where: Material Specifications list, ASTM B348 Grade 2 line
    - system: ASTM
      code: B338
      note: seamless and welded tube
      source: alleima-ti2
      where: Tubing and pipe specifications list, ASTM B338 line
    - system: ASTM
      code: B337
      note: seamless and welded pipe
      source: alleima-ti2
      where: Tubing and pipe specifications list, ASTM B337 line
    - system: ASTM
      code: B381
      note: forgings
      source: austral-wright
      where: ASTM Product Specifications list, B381 row
    - system: ASTM
      code: B861
      note: seamless pipe
      source: tpc-pipe
      where: Seamless pipe table, GRADE 2 row
    - system: ASTM
      code: B862
      note: welded pipe
      source: tpc-pipe
      where: Welded pipe table, GRADE 2 row
    - system: ASTM
      code: B863
      note: wire and rod
      source: tpc-rod-wire
      where: Commercially pure titanium table, GRADE 2 row
    - system: ASTM
      code: F67
      note: sheet, plate and bar
      source: tpc-sheet
      where: Commercially pure titanium table, GRADE 2 row (sheet page)
    - system: ASME
      code: SB-265
      note: strip, sheet and plate
      source: tpc-sheet
      where: Commercially pure titanium table, ASME-SB-265 Grade 2 row
    - system: ASME
      code: SB-348
      note: bars and billets
      source: ti-round-bar
      where: Titanium Grade 2 Round Bar line
    - system: ASME
      code: SB338
      note: seamless and welded tube
      source: alleima-ti2
      where: Tubing and pipe specifications list, ASME SB338 line
    - system: ASME
      code: B862
      note: welded pipe
      source: tpc-pipe
      where: Welded pipe table, ASME B862 on GRADE 2 row
    - system: AMS
      code: '4902'
      note: sheet and plate
      source: tpc-sheet
      where: Commercially pure titanium table, GRADE 2 row
    - system: AMS
      code: '4943'
      note: aerospace hydraulic tubing, annealed
      source: alleima-ti2
      where: Tubing and pipe specifications list, AMS 4943 line
    - system: AMS
      code: '4944'
      note: aerospace hydraulic tubing, cold worked and stress relieved
      source: alleima-ti2
      where: Tubing and pipe specifications list, AMS 4944/4945 line
    - system: AMS
      code: '4945'
      note: aerospace hydraulic tubing, cold worked and stress relieved
      source: alleima-ti2
      where: Tubing and pipe specifications list, AMS 4944/4945 line
    - system: AMS
      code: '4951'
      note: commercially pure weld wire
      source: ti-wire
      where: Titanium Grade 2 Commercially Pure Weld Wire line
tags:
  environments: []
  stresses: []
  applications:
    - thermal-control
    - structures
properties:
  - benchmark: density
    label: Density
    value: 4.51
    unit: g/cm3
    scope: material
    conditions:
      form: seamless tube and pipe (the Alleima datasheet product)
      condition: not stated; alloy density
    method: Printed in the Physical properties section of the Alleima Ti Grade 2 datasheet, which also says the density is 45 % less than ferrous alloys. The Smiths CP Grade 2 datasheet also gives 4.51 g/cc.
    status: ground
    source: alleima-ti2
    where: Physical properties, Density row
  - benchmark: elastic_modulus
    label: Elastic modulus (tension)
    value: 103
    unit: GPa
    scope: material
    conditions:
      form: seamless tube and pipe
      loading: tension
      condition: not stated
    method: Printed in the Elastic modulus section of the Alleima datasheet, tension row (15.0 x 10^6 psi and 103 GPa). The Smiths datasheet prints the same 103 GPa as a typical value.
    status: ground
    source: alleima-ti2
    where: Elastic modulus section, Tension (E) row
  - benchmark: beta_transus
    label: Beta transus
    value: 913
    unit: °C
    scope: material
    conditions:
      form: seamless tube and pipe
      condition: not stated
      printed_as: 1675 F
    method: Printed as 1675F (913C) in the Physical properties section of the Alleima datasheet. The Celsius value is used.
    status: ground
    source: alleima-ti2
    where: Physical properties, Beta transus row
  - benchmark: thermal_conductivity
    label: Thermal conductivity at room temperature
    value: 22
    unit: W/(m·K)
    scope: material
    conditions:
      form: seamless tube and pipe
      temperature: room temperature (printed RT)
      unit_in_source: W/m'C (the degree sign is printed as an apostrophe)
    method: Printed as 22 W/m'C (12.7 BTU) at RT in the Thermal Conductivity section of the Alleima datasheet. The number is the same in W/(m·K) because the degree and kelvin intervals are equal.
    status: ground
    source: alleima-ti2
    where: Physical properties, Thermal Conductivity row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, minimum (strip, sheet and plate)
    value: 345
    bound: lower
    unit: MPa
    scope: material
    conditions:
      form: strip, sheet and plate (ASTM B265 product)
      condition: as specified for Grade 2 in ASTM B265-08b Table 1
      minimum: 'yes'
    method: Minimum in Table 1 (Tensile Requirements) of the ASTM B265-08b copy, with 50 ksi printed beside 345 MPa.
    status: ground
    source: astm-b265
    where: Table 1 Tensile Requirements, Grade 2 row, tensile strength min (ksi 50, MPa 345)
  - benchmark: yield_strength
    label: Yield strength, 0.2 % offset, minimum (strip, sheet and plate)
    value: 275
    bound: lower
    unit: MPa
    scope: material
    conditions:
      form: strip, sheet and plate (ASTM B265 product)
      offset: 0.2 %
      minimum: 'yes'
    method: Minimum in Table 1 of the ASTM B265-08b copy, with 40 ksi printed beside 275 MPa. The same row prints a maximum of 450 MPa (65 ksi), which is not recorded here.
    status: ground
    source: astm-b265
    where: Table 1 Tensile Requirements, Grade 2 row, yield strength 0.2 % offset min (ksi 40, MPa 275)
  - benchmark: elongation
    label: Elongation, minimum (strip, sheet and plate)
    value: 20
    bound: lower
    unit: '%'
    scope: material
    conditions:
      form: strip, sheet and plate (ASTM B265 product)
      gauge: 2 in or 50 mm
      minimum: 'yes'
    method: Minimum elongation in Table 1 of the ASTM B265-08b copy.
    status: ground
    source: astm-b265
    where: Table 1 Tensile Requirements, Grade 2 row, elongation in 2 in. or 50 mm min %
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, minimum (seamless tube, ASTM B338)
    value: 345
    bound: lower
    unit: MPa
    scope: material
    conditions:
      form: seamless tube and pipe (ASTM B338 Grade 2)
      condition: cold reduced or cold reduced and annealed, as supplied
      minimum: 'yes'
    method: Printed as Min 50 ksi and 345 MPa in the tensile properties table for Grade 2 to ASTM B338 in the Alleima datasheet.
    status: ground
    source: alleima-ti2
    where: Mechanical properties, ASTM B338 Grade 2 table, Min row, Ultimate Strength
  - benchmark: yield_strength
    label: Yield strength, minimum (seamless tube, ASTM B338)
    value: 275
    bound: lower
    unit: MPa
    scope: material
    conditions:
      form: seamless tube and pipe (ASTM B338 Grade 2)
      condition: cold reduced or cold reduced and annealed, as supplied
      offset: not printed in the table
      minimum: 'yes'
    method: Printed as Min 40 ksi and 275 MPa in the same Alleima table.
    status: ground
    source: alleima-ti2
    where: Mechanical properties, ASTM B338 Grade 2 table, Min row, Yield strength
  - benchmark: elongation
    label: Elongation, minimum (seamless tube, ASTM B338)
    value: 20
    bound: lower
    unit: '%'
    scope: material
    conditions:
      form: seamless tube and pipe (ASTM B338 Grade 2)
      gauge: 2 in
      condition: cold reduced or cold reduced and annealed, as supplied
      minimum: 'yes'
    method: Printed as Elongation 2 in, Min 20 % in the same Alleima table.
    status: ground
    source: alleima-ti2
    where: Mechanical properties, ASTM B338 Grade 2 table, Min row, Elongation 2 in
  - benchmark: reduction_of_area
    label: Reduction of area, minimum
    value: 35
    bound: lower
    unit: '%'
    scope: material
    conditions:
      form: CP Grade 2 product (datasheet covers bar, wire, strip, sheet, plate, foil, forgings and pipe or tube)
      condition: minimum as printed; no separate condition given
      minimum: 'yes'
    method: Printed in the Mechanical Properties table of the Smiths CP Grade 2 datasheet. reduction_of_area is not in the canonical list, so a snake_case name is used (see gaps).
    status: ground
    source: smith-cp2
    where: Mechanical Properties table, Reduction of area row, minimum column
  - benchmark: impact_energy
    label: Charpy V-notch impact, minimum
    value: 41
    bound: lower
    unit: J
    scope: material
    conditions:
      form: CP Grade 2 product (datasheet product range)
      test: Charpy V-notch
      minimum: 'yes'
    method: Printed in the Mechanical Properties table of the Smiths CP Grade 2 datasheet. impact_energy is a snake_case name (see gaps).
    status: ground
    source: smith-cp2
    where: Mechanical Properties table, Charpy V notch impact row, minimum column
  - benchmark: yield_strength
    label: Yield strength, typical
    value: 352
    unit: MPa
    scope: material
    conditions:
      form: CP Grade 2 product (datasheet product range)
      offset: 0.2 %
      basis: typical, not a minimum
    method: Printed as 0.2% PS, typical 352 MPa in the Smiths datasheet. The datasheet minimum of 276 MPa is not used here; the ASTM minimum of 275 MPa is recorded instead.
    status: ground
    source: smith-cp2
    where: Mechanical Properties table, 0.2% PS row, typical column
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, typical
    value: 483
    unit: MPa
    scope: material
    conditions:
      form: CP Grade 2 product (datasheet product range)
      basis: typical, not a minimum
    method: Printed in the UTS row, typical column, of the Smiths CP Grade 2 datasheet.
    status: ground
    source: smith-cp2
    where: Mechanical Properties table, UTS row, typical column
  - benchmark: elongation
    label: Elongation, typical
    value: 28
    unit: '%'
    scope: material
    conditions:
      form: CP Grade 2 product (datasheet product range)
      gauge: 2 in
      basis: typical, not a minimum
    method: Printed in the Elongation on 2 in row, typical column, of the Smiths CP Grade 2 datasheet.
    status: ground
    source: smith-cp2
    where: Mechanical Properties table, Elongation on 2 in row, typical column
  - benchmark: hardness
    label: Hardness, typical
    value: 160
    unit: HV
    scope: material
    conditions:
      form: CP Grade 2 product (datasheet product range)
      basis: typical
    method: Printed as Hardness HV, typical 160, in the Smiths CP Grade 2 datasheet.
    status: ground
    source: smith-cp2
    where: Mechanical Properties table, Hardness HV row, typical column
  - benchmark: hardness
    label: Hardness, maximum
    value: 92
    bound: upper
    unit: HRB
    scope: material
    conditions:
      form: seamless tube and pipe
      condition: supplied as cold reduced or cold reduced and annealed
    method: Printed as 92 HRB max. in the Hardness section of the Alleima datasheet.
    status: ground
    source: alleima-ti2
    where: Hardness section, 92 HRB max.
corrosion:
  - environment: Seawater and brines, general corrosion
    headline: Excellent resistance to general corrosion in seawater and brines.
    effect: Alleima says CP titanium has excellent resistance to general corrosion in seawater, and lists seawater and brines among the media where it shows good corrosion resistance. The datasheet prints no test conditions.
    rating: low
    conditions:
      basis: manufacturer statement; no test conditions printed
      form: seamless tube and pipe (Alleima datasheet)
    source: alleima-ti2
    where: Features list; Corrosion resistance, General corrosion section
  - environment: Chlorides and common salt solutions, pH 3 to 12
    headline: Resists most natural waters and common salt solutions, including chlorides, from pH 3 to 12.
    effect: Titanium Industries says titanium alloys are usually expected to resist most natural waters and common salt solutions, including chlorides, in a pH range of 3 to 12. The statement is for titanium alloys in general, not a Grade 2 test.
    rating: low
    conditions:
      basis: general statement for titanium alloys; no Grade 2 test conditions
      pH: 3 to 12
    source: titanium-industries
    where: Titanium Performance in Seawater Applications, introduction and FAQ
  - environment: Crevice corrosion below 80 °C
    headline: No crevice corrosion expected below 80 °C at any pH, even in super-chlorinated water.
    effect: Alleima says CP titanium will not exhibit crevice corrosion at temperatures under 80 °C regardless of pH, even under super-chlorinated conditions, and resists crevice attack in salt solutions better than stainless steels.
    rating: low
    conditions:
      temperature: below 80 °C
      pH: any
      chlorides: super-chlorinated
    source: alleima-ti2
    where: Crevice corrosion section
  - environment: Near-anaerobic seawater at 80 °C and above
    headline: Grade 2 suffers crevice corrosion at 80 °C in near-anaerobic seawater.
    effect: Pang and Blackwood tested Grades 2, 5 and 7 in near-anaerobic seawater (below 1 ppm oxygen) up to 200 °C, with and without CO2. The abstract says Grade 2 suffers crevice corrosion at 80 °C and Grade 5 at 200 °C.
    rating: moderate
    conditions:
      electrolyte: seawater, near-anaerobic (below 1 ppm oxygen)
      temperature: up to 200 °C; crevice attack for Grade 2 at 80 °C
      CO2: tested with and without CO2
    source: pang-2016
    where: Abstract (Corrosion Science 105, 2016)
  - environment: Hot chloride solutions and seawater (stress corrosion cracking)
    headline: Excellent resistance to stress corrosion cracking; immune in seawater.
    effect: Alleima says Grade 2 shows excellent resistance to stress corrosion cracking in hot chloride solutions and is immune to SCC in seawater. Titanium Industries says titanium does not show the same susceptibility to chloride stress corrosion as stainless steel.
    rating: low
    conditions:
      basis: manufacturer statements; no test conditions printed
    source: alleima-ti2
    where: Stress corrosion cracking section
  - environment: Flowing seawater (erosion)
    headline: Negligible erosion in flowing seawater up to 40 m/s.
    effect: Alleima says titanium shows excellent resistance to erosion in flowing seawater up to 130 ft/s (40 m/s), with negligible effect. Sand has only a small effect.
    rating: low
    conditions:
      velocity: up to 40 m/s (130 ft/s)
      medium: flowing seawater
    source: alleima-ti2
    where: Erosion corrosion section
  - environment: Galvanic coupling
    headline: Titanium is normally the cathode and can accelerate corrosion of a coupled metal.
    effect: Alleima says titanium is near the noble end of the galvanic series and normally acts as the cathode. It is not itself affected by galvanic corrosion, but it can accelerate corrosion of the metal it is coupled to.
    rating: moderate
    conditions:
      basis: galvanic series position; no test conditions printed
    source: alleima-ti2
    where: Galvanic corrosion section
  - environment: Strong reducing acids, fluoride solutions, pure oxygen, anhydrous chlorine
    headline: Should not be used with these media.
    effect: Alleima says titanium should not be used with strong reducing acids, fluoride solutions, pure oxygen or anhydrous chlorine. The datasheet prints no concentrations.
    rating: severe
    conditions:
      basis: manufacturer advice; no concentrations printed
    source: alleima-ti2
    where: Corrosion resistance section, opening statement
  - environment: Hydrogen pickup in seawater
    headline: No significant hydrogen absorption in seawater unless three conditions are met together.
    effect: Alleima says hydrogen absorption normally occurs only when the pH is below 3 or above 12, the temperature is above 80 °C, and a hydrogen source such as a galvanic couple or impressed current is present.
    rating: low
    conditions:
      basis: conditional; all three conditions must be met
    source: alleima-ti2
    where: Hydrogen embrittlement section
  - environment: General corrosion (product description)
    headline: Outstanding corrosion resistance, with strength similar to austenitic stainless steels.
    effect: Austral Wright describes Grade 2 as a commercially pure titanium grade with outstanding corrosion resistance and useful strength, similar to austenitic stainless steels. The description prints no test conditions.
    rating: low
    conditions:
      basis: product description; no test conditions
    source: austral-wright
    where: Product description on the Titanium Grade 2 page
risks:
  hazards:
    - text: PubChem aggregates GHS reports for titanium (CID 23963). It gives H228 (flammable solid), signal word Danger, and lists Flammable solids Category 1. The record does not separate bulk metal from powder or swarf. Check the SDS for the form you handle.
      ghs:
        - 'H228: Flammable solid'
      source: pubchem-ti
      where: Safety and Hazards, GHS Classification (CID 23963)
    - text: Precautionary statement codes listed with the GHS entry include P210, P240, P241 and P280.
      ghs: []
      source: pubchem-ti
      where: Safety and Hazards, GHS precautionary statements
  failure_risks:
    - mode: Crevice corrosion in hot seawater from 80 °C
      trigger: Tight crevices in seawater at 80 °C and above
      consequence: Local attack in the crevice; Pang and Blackwood report it for Grade 2 at 80 °C in near-anaerobic seawater
      severity: moderate
      source: pang-2016
      where: Abstract (Corrosion Science 105, 2016)
    - mode: Use in media titanium should not be used with
      trigger: Strong reducing acids, fluoride solutions, pure oxygen or anhydrous chlorine
      consequence: Alleima advises against these media; no concentrations are printed
      severity: high
      source: alleima-ti2
      where: Corrosion resistance section, opening statement
    - mode: Galvanic coupling to a less noble metal
      trigger: Electrical contact with a less noble metal in an electrolyte
      consequence: Titanium acts as the cathode and accelerates corrosion of the coupled metal
      severity: moderate
      source: alleima-ti2
      where: Galvanic corrosion section
    - mode: Galling of the tube bore and springback in bending
      trigger: Bending thin-walled tube or using a tight radius without a well-lubricated mandrel
      consequence: Galling of the ID surface; springback about twice that of stainless steel
      severity: low
      source: alleima-ti2
      where: Fabrication, Bending section
  side_effects: []
  handling:
    - text: Weldability is excellent. Specified bend radius is 2.0 times thickness for sections under 0.070 in and 2.5 times thickness above that. Welded bend radius is 3.0 times thickness at minimum.
      source: smith-cp2
      where: Fabrication section
    - text: Welding is regularly done by TIG. Inert gas shielding must cover both OD and ID of tube, the surface must be free of grease and oil, a low heat input is used, and no post-weld heat treatment is normally performed.
      source: alleima-ti2
      where: Weldability section
    - text: Bend thin-walled tube with a well-lubricated mandrel to prevent galling of the ID surface. Allow for springback about twice that of stainless steel.
      source: alleima-ti2
      where: Fabrication, Bending section
    - text: 'Machining: use low cutting speeds and high feed rates, large volumes of coolant, sharp tools, and never stop feeding while the tool is in contact with the workpiece.'
      source: alleima-ti2
      where: Fabrication, Machining and cutting section
    - text: Do not use with strong reducing acids, fluoride solutions, pure oxygen or anhydrous chlorine.
      source: alleima-ti2
      where: Corrosion resistance section, opening statement
  mitigations: []
uses:
  - application: thermal-control
    device: Seawater-cooled heat exchanger and condenser tubing
    example: Alleima lists tubing for heat exchangers and coolers on oil platforms, in refineries and in chemical plants that use seawater or chlorinated seawater as coolant. It also lists heat exchangers where the process contains chlorides, sulfides, organic acids, nitric acid or wet chlorine.
    source: alleima-ti2
    where: Typical applications, seawater cooling and refineries sections
  - application: structures
    device: Desalination pipe and reverse-osmosis pressure vessels
    example: Alleima lists tube and pipe for seawater transport, heat-exchanger tubing and pressure vessels for reverse-osmosis units in desalination plants.
    source: alleima-ti2
    where: Typical applications, desalination plants section
  - application: structures
    device: Aerospace hydraulic tubing (AMS 4943 annealed; AMS 4944 and 4945 cold worked and stress relieved)
    example: Alleima lists these aerospace hydraulic tubing specifications for its Grade 2 tubing, together with ASTM B337 and B338 for pipe and tube.
    source: alleima-ti2
    where: Tubing and pipe specifications list
supply:
  - subject: Titanium sponge (feedstock for titanium mill products)
    abundance: The USGS 2026 titanium summary fetched for this profile gives no crustal abundance or resource tonnage. It refers to a separate titanium mineral concentrates chapter.
    producers:
      - country: China
        share_percent: 70.3
        year: 2025
        basis: 'computed: 260,000 t of 370,000 t world sponge (USGS table, World Sponge Metal Production)'
      - country: Japan
        share_percent: 14.3
        year: 2025
        basis: 'computed: 53,000 t of 370,000 t'
      - country: Russia
        share_percent: 6.8
        year: 2025
        basis: 'computed: 25,000 t of 370,000 t'
      - country: Kazakhstan
        share_percent: 4.3
        year: 2025
        basis: 'computed: 16,000 t of 370,000 t'
      - country: Saudi Arabia
        share_percent: 3.2
        year: 2025
        basis: 'computed: 12,000 t of 370,000 t'
    us_position: The United States produced no titanium sponge in 2025; the last domestic sponge plant closed in 2024. U.S. imports of sponge were an estimated 44,000 tons in 2025 (Japan 73 %, Kazakhstan 13 %, Saudi Arabia 13 % through July 2025).
    source: usgs-ti-2026
    where: Domestic Production and Use; Events, Trends, and Issues; World Sponge Metal Production table
media: []
documents:
  - title: 'Smiths Metal Centres: CP Grade 2 technical datasheet'
    type: datasheet
    url: https://www.smithmetal.com/pdf/titanium/cp-grade-2.pdf
    year: 2023
  - title: 'Alleima: Ti Grade 2 seamless tube and pipe datasheet'
    type: datasheet
    url: https://alleima.com/contentassets/a495aa0b17a443d395a07671faa5fc30/datasheet-alleima-ti-grade-2-en-v2024-01-11-1032-version-1.pdf/download
    year: 2024
  - title: 'ASTM B265-08b: Titanium and Titanium Alloy Strip, Sheet, and Plate (copy hosted by GS Alloy)'
    type: standard
    url: https://gsalloy.com/wp-content/uploads/2024/04/ASTM-B265.pdf
    year: 2008
  - title: 'USGS Mineral Commodity Summaries 2026: Titanium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf
    year: 2026
  - title: 'PubChem: Titanium (CID 23963), GHS classification (PUG View JSON)'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23963/JSON
    year: 2026
  - title: 'Pang and Blackwood (2016): Corrosion of titanium alloys in high temperature near anaerobic seawater, Corrosion Science 105'
    type: paper
    url: https://tethys-engineering.pnnl.gov/publications/corrosion-titanium-alloys-high-temperature-near-anaerobic-seawater
    year: 2016
  - title: 'Titanium Processing Center: titanium sheet product page (commercially pure titanium specifications list)'
    type: datasheet
    url: https://www.titaniumprocessingcenter.com/products/titanium-sheet/
    year: 2026
  - title: 'Titanium Processing Center: titanium pipe product page (seamless and welded pipe, specifications list)'
    type: datasheet
    url: https://www.titaniumprocessingcenter.com/products/titanium-pipe/
    year: 2026
  - title: 'Titanium Processing Center: titanium rod and wire rod product page (commercially pure titanium specifications list)'
    type: datasheet
    url: https://www.titaniumprocessingcenter.com/products/titanium-rod-wire-rod/
    year: 2026
  - title: 'Titanium Industries: mill product, titanium round bar (specifications list)'
    type: datasheet
    url: https://qqa.titanium.com/product/mill-product-titanium-round-bar
    year: 2026
  - title: 'Titanium Industries: mill product, titanium wire (specifications list)'
    type: datasheet
    url: https://qqa.titanium.com/product/mill-product-titanium-wire
    year: 2026
gaps:
  - 'Melting point: the Alleima datasheet prints it as 3020 F with the Celsius value shown as l 660 C in the PDF text. Not 1660 as digits, so no number is recorded.'
  - 'Specific heat, coefficient of thermal expansion and Poisson''s ratio: no numeric value in the datasheets fetched for this profile. Alleima says very low thermal expansion without a number.'
  - 'Unreachable: the Ulbrich Grade 2 datasheet returned a Cloudflare challenge, the LBL CP Titanium Grade 2 PDF returned 404, and the MakeItFrom Grade 2 page did not load. None of their values is used.'
  - 'Standard edition: the ASTM B265 copy is the 2008b edition (its header says B 265 - 08b). The ASTM store lists a later revision; check the current edition before specifying.'
  - 'Composition conflict: the Smiths datasheet prints C max 0.1 and H max 0.0125 for bar, while ASTM B265-08b Table 2 gives C max 0.08 and H max 0.015. The ASTM values are used. Alleima prints nominal values only.'
  - 'ASTM B348 (bar): the Smiths datasheet lists B348 Grade 2, but the bar tensile table was not fetched. Bar strengths are not recorded separately.'
  - 'Yield maximum: ASTM prints 450 MPa as the upper limit of the yield range; it is not recorded. The Smiths datasheet minimum of 276 MPa conflicts with ASTM 275 MPa, and the ASTM value is used.'
  - 'Crevice temperature conflict: Alleima says no crevice attack below 80 °C, Pang and Blackwood report attack at 80 °C in near-anaerobic seawater, and the Austral Wright page fetched for this profile prints no crevice temperature.'
  - 'Seawater temperature limit for general corrosion, and any chloride data for Grade 2 in open-access papers: no open-access journal article beyond the Pang and Blackwood abstract was fetched.'
  - 'Space and orbital data (atomic oxygen erosion, outgassing, thermal cycling in orbit, cryogenic properties): no NASA or NIST source with Grade 2 numbers was fetched.'
  - 'Hydrogen embrittlement and galling: only qualitative statements from Alleima; no numeric limits were fetched. Fatigue endurance limit: Alleima says fatigue is unchanged in seawater but prints no number.'
  - 'Critical-mineral lists: the USGS 2026 titanium summary fetched here does not list them. The EU and USGS critical lists were not fetched.'
  - Atomic weights of the constituents were not fetched, so recipe parts carry share limits only.
  - 'Medical implant use: Wikipedia says CP titanium has been used for orthopaedic and dental implants, but the medical application is not in the allowed application list and is not recorded as a use.'
  - 'Property names: reduction_of_area, impact_energy and beta_transus are not in spores/property-canon.yaml and use snake_case names.'
  - 'Product forms: the Smiths datasheet covers bar, wire, strip, sheet, plate, foil, extrusions, forgings and pipe, but its values are not split by form.'
  - 'Designations not found: EN 3.7035 (W.Nr.), DIN, EN name, ISO (5832-2), JIS (TP340, class 2), GB (TA2) and AMS 4941 are printed on none of the pages read in this run. Not reached: ATI product URLs return the homepage; Carpenter alloy finder is JavaScript only; asm.matweb.com returned nothing and the asminternational.org homepage prints no grade; Online Metals, Metals Depot and MatWeb show a Cloudflare challenge; TIMET product pages print no grade. Not recorded: the Smiths BS TA 2 to 5 range, AIR 9182 T-40, AWS A5.16 ERTi-2 and the MIL-T-9046 and AMS-T-9046 CP-3 class codes.'
sources:
  smith-cp2:
    title: CP Grade 2 Technical Datasheet (Smiths Metal Centres)
    id: Smiths Metal Centres
    url: https://www.smithmetal.com/pdf/titanium/cp-grade-2.pdf
    year: 2023
    kind: datasheet
    license: supplier datasheet, cited not reproduced
  alleima-ti2:
    title: 'Alleima Ti Grade 2 tube and pipe, seamless: datasheet (updated 2024-01-11)'
    id: Alleima
    url: https://alleima.com/contentassets/a495aa0b17a443d395a07671faa5fc30/datasheet-alleima-ti-grade-2-en-v2024-01-11-1032-version-1.pdf/download
    year: 2024
    kind: datasheet
    license: supplier datasheet, cited not reproduced
  astm-b265:
    title: 'ASTM B265-08b: Standard Specification for Titanium and Titanium Alloy Strip, Sheet, and Plate (copy hosted by GS Alloy)'
    id: ASTM B265-08b
    url: https://gsalloy.com/wp-content/uploads/2024/04/ASTM-B265.pdf
    year: 2008
    kind: standard
    license: standard copy, cited not reproduced
  usgs-ti-2026:
    title: 'Mineral Commodity Summaries 2026: Titanium (USGS, February 2026)'
    id: USGS MCS 2026, Titanium
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf
    year: 2026
    kind: report
    license: US Government work, public domain
  pubchem-ti:
    title: 'PubChem: Titanium (CID 23963), GHS classification and identifiers'
    id: PubChem CID 23963
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23963/JSON
    year: 2026
    kind: database
    license: PubChem, public
  pang-2016:
    title: Corrosion of titanium alloys in high temperature near anaerobic seawater (Pang and Blackwood, Corrosion Science 105, 2016)
    id: Pang and Blackwood, Corrosion Science 2016
    url: https://tethys-engineering.pnnl.gov/publications/corrosion-titanium-alloys-high-temperature-near-anaerobic-seawater
    year: 2016
    kind: paper
    license: abstract page, cited not reproduced
  titanium-industries:
    title: Titanium Performance in Seawater Applications (Titanium Industries)
    id: Titanium Industries technical data
    url: https://titanium.com/technical-references/titanium-seawater-applications
    year: 2026
    kind: web
    license: supplier web page, cited not reproduced
  wiki-ti-alloy:
    title: Titanium alloy (Wikipedia)
    id: Wikipedia, Titanium alloy
    url: https://en.wikipedia.org/wiki/Titanium_alloy
    year: 2026
    kind: web
    license: CC BY-SA 4.0
  austral-wright:
    title: Titanium Grade 2 (Austral Wright Metals product page)
    id: Austral Wright Metals
    url: https://www.australwright.com.au/technical-data/alloys/high-performance-alloys/titanium-alloy-grade-2/
    year: 2026
    kind: web
    license: supplier web page, cited not reproduced
  tpc-sheet:
    title: 'Titanium Processing Center: titanium sheet product page (commercially pure titanium specifications list)'
    id: Titanium Processing Center
    url: https://www.titaniumprocessingcenter.com/products/titanium-sheet/
    year: 2026
    kind: web
    license: supplier web page, cited not reproduced
  tpc-pipe:
    title: 'Titanium Processing Center: titanium pipe product page (seamless and welded pipe, specifications list)'
    id: Titanium Processing Center
    url: https://www.titaniumprocessingcenter.com/products/titanium-pipe/
    year: 2026
    kind: web
    license: supplier web page, cited not reproduced
  tpc-rod-wire:
    title: 'Titanium Processing Center: titanium rod and wire rod product page (commercially pure titanium specifications list)'
    id: Titanium Processing Center
    url: https://www.titaniumprocessingcenter.com/products/titanium-rod-wire-rod/
    year: 2026
    kind: web
    license: supplier web page, cited not reproduced
  ti-round-bar:
    title: 'Titanium Industries: mill product, titanium round bar (specifications list)'
    id: Titanium Industries
    url: https://qqa.titanium.com/product/mill-product-titanium-round-bar
    year: 2026
    kind: web
    license: supplier web page, cited not reproduced
  ti-wire:
    title: 'Titanium Industries: mill product, titanium wire (specifications list)'
    id: Titanium Industries
    url: https://qqa.titanium.com/product/mill-product-titanium-wire
    year: 2026
    kind: web
    license: supplier web page, cited not reproduced
license: CC-BY-4.0
updated: '2026-10-24'
review:
  status: draft
  method: assistant
  checked_values: 17
  unreachable: 3
  caveats: 3
  note: 'Written 2026-10-24 by an assistant from pages fetched in this run: Smiths and Alleima datasheets, ASTM B265-08b copy, USGS MCS 2026 titanium, PubChem, the Pang and Blackwood abstract, Titanium Industries, Wikipedia and Austral Wright. Ulbrich, LBL and MakeItFrom were not readable and are not used.'
story:
  recipe:
    line: Unalloyed titanium with no deliberate alloying additions. ASTM B265 limits the grade 2 composition to maximum oxygen, iron, carbon, nitrogen and hydrogen, with titanium as the balance. Wikipedia lists Grade 2 as the standard-oxygen unalloyed grade. Process routes are not described in the sources fetched for this profile.
    parts:
      - name: Titanium
        symbol: Ti
        share_note: balance (the rest)
        role: Base metal. Gives the low density and the oxide-film corrosion resistance.
        source: smith-cp2
        where: Chemical Composition table, Ti balance
      - name: Oxygen
        symbol: O
        share_high: 0.25
        share_note: maximum 0.25 %
        role: Interstitial impurity with a maximum limit.
        source: astm-b265
        where: Table 2 Chemical Requirements, Oxygen max, Grade 2 column
      - name: Iron
        symbol: Fe
        share_high: 0.3
        share_note: maximum 0.30 %
        role: Impurity with a maximum limit.
        source: astm-b265
        where: Table 2 Chemical Requirements, Iron max, Grade 2 column
      - name: Carbon
        symbol: C
        share_high: 0.08
        share_note: maximum 0.08 %
        role: Interstitial impurity with a maximum limit.
        source: astm-b265
        where: Table 2 Chemical Requirements, Carbon max, Grade 2 column
      - name: Nitrogen
        symbol: 'N'
        share_high: 0.03
        share_note: maximum 0.03 %
        role: Interstitial impurity with a maximum limit.
        source: astm-b265
        where: Table 2 Chemical Requirements, Nitrogen max, Grade 2 column
      - name: Hydrogen
        symbol: H
        share_high: 0.015
        share_note: maximum 0.015 %
        role: Interstitial impurity with a maximum limit.
        source: astm-b265
        where: Table 2 Chemical Requirements, Hydrogen max, Grade 2 column
  risk_groups:
    - title: For people
      level: 1
      verdict: 'Solid: no class. Powder and swarf: flammable'
      lead: The solid metal is not hazard-classed in the sources fetched here. PubChem gives titanium a flammable-solid classification (H228), which applies to powder and swarf.
      points:
        - label: Solid metal
          line: Sheet, plate, bar and tube are covered by the Smiths and Alleima datasheets, which carry no hazard classification.
        - label: Powder and swarf
          line: PubChem gives H228 (flammable solid) from aggregated reports. Treat powder and swarf as a fire hazard.
  why: Grade 2 is the most frequently employed unalloyed titanium grade (Smiths). It combines moderate strength with good ductility, formability and excellent weldability, and it resists seawater and chloride environments (Alleima). It is chosen when corrosion resistance and formability matter more than strength.
  uses:
    - where: Seawater cooling and heat exchangers
      line: Alleima lists tubing for heat exchangers and coolers that use seawater or chlorinated seawater as coolant, on oil platforms, in refineries and in chemical plants.
    - where: Desalination
      line: Alleima lists tube and pipe for seawater transport, heat-exchanger tubing and pressure vessels for reverse-osmosis units.
    - where: Aerospace hydraulic tubing
      line: Alleima lists AMS 4943 (annealed) and AMS 4944 and 4945 (cold worked and stress relieved) for hydraulic tubing in this grade.
  can_do:
    - label: Strength
      benchmark: ultimate_tensile_strength
      line: Minimum tensile strength 345 MPa and minimum 0.2 % yield strength 275 MPa for strip, sheet and plate (ASTM B265). Typical values in the Smiths datasheet are 483 MPa tensile and 352 MPa yield.
    - label: Ductility
      benchmark: elongation
      line: Minimum elongation 20 % (ASTM B265, 2 in or 50 mm gauge). Typical 28 % in the Smiths datasheet.
    - label: Stiffness
      benchmark: elastic_modulus
      line: Elastic modulus 103 GPa in tension, roughly one-half that of steel alloys (Alleima).
    - label: Corrosion
      line: Resists seawater, brines and chlorides (Alleima and Titanium Industries). Crevice attack is not expected below 80 °C (Alleima).
  compare: Grade 2 is the lower-strength titanium. The stronger alloy is [Ti-6Al-4V](/materials/ti-6al-4v). Grade 2 has a minimum tensile strength of 345 MPa and a minimum 0.2 % yield strength of 275 MPa (ASTM B265). Its elastic modulus of 103 GPa is roughly half that of steel alloys, and its density of 4.51 g/cm3 is 45 % less than ferrous alloys (Alleima).
  compare_rows:
    - scope: material
      label: Density
      benchmark: density
    - scope: material
      label: Elastic modulus
      benchmark: elastic_modulus
    - scope: material
      label: Yield strength
      benchmark: yield_strength
  handling:
    - 'Welding: TIG is the usual method. Shield both OD and ID of tube with inert gas, keep the surface free of grease and oil, use a low heat input, and no post-weld heat treatment is normally needed (Alleima).'
    - 'Bending: use a well-lubricated mandrel on thin-walled tube and allow for springback about twice that of stainless steel (Alleima). Bend radius is 2.0 times thickness below 0.070 in and 2.5 times above (Smiths).'
    - 'Machining: low cutting speed, high feed, plenty of coolant, sharp tools, and never stop feeding while the tool is in contact (Alleima).'
  good_for:
    - Seawater cooling tubing and heat exchangers, where chloride resistance is needed (Alleima).
    - Forming and welding of sheet, plate and tube where ductility and weldability matter more than strength (Smiths).
    - Desalination pipe and reverse-osmosis pressure vessels (Alleima).
  watch_out:
    - 'Crevice attack in chloride: none expected below 80 °C, but Grade 2 crevice-corroded at 80 °C in near-anaerobic seawater (Alleima; Pang and Blackwood).'
    - 'Lower strength than Ti-6Al-4V: 345 MPa minimum tensile (see the Ti-6Al-4V profile).'
    - Do not use with strong reducing acids, fluoride solutions, pure oxygen or anhydrous chlorine (Alleima).
    - Springback is about twice that of stainless steel in bending (Alleima).
    - Powder and swarf are a flammable-solid fire hazard (PubChem).
  verdict: CP titanium Grade 2 is the corrosion-resistant, formable titanium grade for seawater and chloride service. Its strength is modest, with a 345 MPa minimum tensile strength, so it is not a structural alloy like Ti-6Al-4V. Its limits are crevice attack in hot seawater and the media it should not be used in.
composition:
  basis: weight percent, ASTM B265-08b Table 2, Grade 2 column
  source: astm-b265
  where: Table 2 Chemical Requirements, Grade 2 column
  limits:
    - element: O
      max: 0.25
    - element: Fe
      max: 0.3
    - element: C
      max: 0.08
    - element: 'N'
      max: 0.03
    - element: H
      max: 0.015
  note: ASTM B265-08b Table 2 prints Fe max 0.30 and O max 0.25 for Grade 2. Smiths prints C max 0.1 and H max 0.0125 for bar; Alleima prints nominal values only. The ASTM values are used.
critical_lists: []
supply_note: Shares are computed by the assistant from the printed tonnage and the printed world total (USGS rounds its world totals), not printed by USGS.