Commercially pure titanium, Grade 3 (UNS R50550) CP Ti Grade 3

Unalloyed titanium, UNS R50550 (ASTM Grade 3): maximum limits on O, Fe, C, N and H, titanium the balance · CAS 7440-32-6

Also known as UNS R50550, EN 3.7055, ASTM B265, ASTM B348, ASTM F67, ASME SB-265 · 5 more

Commercially pure (CP) titanium Grade 3, UNS R50550, is unalloyed titanium with a higher oxygen limit than Grades 1 and 2.

8 sources · Updated 2026-10-26 · CC BY 4.0

Evidence level

2 of 5

Lab-measured

Strength

> 450 MPa

Ductility

> 18 %

Stiffness

103 GPa

Recipe, share of the weight

  • Ti balance (the rest)Titanium
  • O maximum 0.35 %Oxygen
  • Fe maximum 0.3 %Iron
  • C maximum 0.08 %Carbon
  • N maximum 0.05 %Nitrogen
  • H maximum 0.015 %Hydrogen

Best for

Formed and welded parts that need more strength than Grade 2 while keeping weldability and corrosion resistance in oxidising, neutral and mildly reducing media (Smiths)

Weakest at

Strength: 450 MPa minimum tensile, well below Ti-6Al-4V (see the Ti-6Al-4V profile). Oxygen limit of 0.35 %, the highest of CP grades 1 to 3 in ASTM B265 Table 2

Risk at a glance

  • People Low. Solid: no class. Powder and swarf: flammable
  • If it fails Moderate. Bending tighter than the specified radius
  • Corrosion Low. High corrosion resistance in oxidising, neutral and mildly reducing media, including chlorides.

Quick facts: CP Ti Grade 3

Key properties of CP Ti Grade 3
PropertyValueBasis
Density4.51 g/cm³1 sourced value
Yield strength380 to 462 MPa2 sourced values across conditions
Tensile strength450 to 593 MPa2 sourced values across conditions
Young's modulus103 GPa1 sourced value
Thermal conductivity21.8 W/(m·K)1 sourced value
Thermal expansion (CTE)8.6 ppm/K1 sourced value

What is the density of Commercially pure titanium, Grade 3 (UNS R50550)?

Commercially pure titanium, Grade 3 (UNS R50550) has a density of 4.51 g/cm³. The source and test conditions are listed in the properties table on this page.

What is the thermal conductivity of Commercially pure titanium, Grade 3 (UNS R50550)?

Commercially pure titanium, Grade 3 (UNS R50550) has a thermal conductivity of 21.8 W/(m·K). The source and test conditions are listed in the properties table on this page.

What is the coefficient of thermal expansion of Commercially pure titanium, Grade 3 (UNS R50550)?

Commercially pure titanium, Grade 3 (UNS R50550) has a coefficient of thermal expansion of 8.6 ppm/K. The source and test conditions are listed in the properties table on this page.

What is the yield strength of Commercially pure titanium, Grade 3 (UNS R50550)?

Commercially pure titanium, Grade 3 (UNS R50550) has a yield strength of 380 to 462 MPa. The range covers 2 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 Commercially pure titanium, Grade 3 (UNS R50550)?

Commercially pure titanium, Grade 3 (UNS R50550) has a tensile strength of 450 to 593 MPa. The range covers 2 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 Commercially pure titanium, Grade 3 (UNS R50550)?

Commercially pure titanium, Grade 3 (UNS R50550) is also written as UNS R50550, EN 3.7055, ASTM B265, ASTM B348, ASTM F67, ASME SB-265. Each code is printed in the source listed beside it in the designations table.

What is Commercially pure titanium, Grade 3 (UNS R50550) used for?

Uses recorded in the sources include Matrix plates for shell and tube heat exchangers; Aerospace sheet, plate and strip to AMS 4900; Architecture, automotive, chemical plant and marine components and equipment.

Why it exists

Grade 3 is the commercially pure titanium with the highest minimum tensile strength of Grades 1 to 3 in ASTM B265 Table 1. It keeps the formability and weldability of the CP grades, with 18 % minimum elongation and a typical 25 % in the Smiths datasheet. It is chosen where CP titanium must be stronger than Grade 2 and corrosion resistance in oxidising, neutral and mildly reducing media is enough.

Where it's used

Heat exchangers

Alleima says the grade is typically used for matrix plates in shell and tube heat exchangers.

Aerospace sheet and plate

United Performance Metals lists aerospace structures among its applications for Grade 3 sheet and coil to AMS 4900.

Architecture and industrial equipment

Smiths lists architecture, automotive, chemical plant and marine industries among the typical applications for CP Grade 3.

Recipe

Unalloyed titanium, UNS R50550 (ASTM Grade 3): maximum limits on O, Fe, C, N and H, titanium the balance

Unalloyed titanium with no deliberate alloying additions. ASTM B265 limits Grade 3 to maximum oxygen, iron, carbon, nitrogen and hydrogen, with titanium as the balance. Process routes are not described in the sources read.

What CP Ti Grade 3 is made of
IngredientShare of the weightWhat it does
Titanium Ti balance (the rest) Base metal. Gives the low density and the oxide-film corrosion resistance.
Oxygen O maximum 0.35 % Interstitial impurity with a maximum limit. ASTM B265 Table 2 gives Grade 3 the highest oxygen limit of Grades 1 to 3.
Iron Fe maximum 0.3 % Impurity with a maximum limit.
Carbon C maximum 0.08 % Interstitial impurity with a maximum limit.
Nitrogen N maximum 0.05 % Interstitial impurity with a maximum limit. Grade 3 allows more nitrogen than Grades 1 and 2 (0.03 %).
Hydrogen H maximum 0.015 % Interstitial impurity with a maximum limit.

Weight shares are as printed in the sources.

What it can do

Strength

> 450 MPa

measured

Minimum tensile strength 450 MPa and minimum 0.2 % yield strength 380 MPa for strip, sheet and plate (ASTM B265). Typical values in the Smiths datasheet are 593 MPa tensile and 462 MPa yield.

Ductility

> 18 %

measured

Minimum elongation 18 % (ASTM B265, 2 in or 50 mm gauge). Typical 25 % in the Smiths datasheet.

Stiffness

103 GPa

measured

Elastic modulus 103 GPa, typical (Smiths). The UPM datasheet prints 15.2 to 17.4 Msi.

Corrosion

Smiths rates high corrosion resistance in oxidising, neutral and mildly reducing media, including chlorides.

Weldability

Smiths rates weldability as excellent.

How it compares

Grade 3 has the highest minimum tensile strength and yield strength of unalloyed grades 1 to 3 in ASTM B265 Table 1, at 450 MPa tensile and 380 MPa yield. The stronger alloy is [Ti-6Al-4V](/materials/ti-6al-4v), which is not a commercially pure grade.

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.

Benchmarks
MeasurementCP Ti Grade 3CP Ti Grade 2Ti-6Al-4VTi-6Al-4V ELITi-3Al-2.5V (Grade 9)TiAlBeta 3Ti Grade 11Ti Gr 12CP Ti Grade 7Ti minor alloys
Capacity and energy
Charpy V-notch impact, minimum> 20 J13> 41 J18 Jno data> 48 Jno datano datano datano datano datano data
Thermal behavior and safety
Thermal conductivity151.2 Btu-in/(hr·ft²·°F)522 W/(m·K)6.7 W/(m K)6.6 W/(m K)no datano datano data21.79 W/(m·K)19.02 W/(m·K)21.79 W/m-K46.8 BTU-in/hr-ft2-°F
Physical and electrical
Density4.51 g/cm³14.51 g/cm³4.43 g/cm³4.42 g/cm³4.48 g/cm³3.8 g/cm³5.07 g/cm³4.51 g/cm³4.51 g/cm³4.51 g/cm³4.54 g/cm³
Hardness, typical200 HV14160 HV30 HRCno data15 HRCno data24 to 38 HRCno datano datano data24 to 38 HRC
Hardness, maximum (bar and billet)< 90 HRB15160 HV30 HRCno data15 HRCno data24 to 38 HRCno datano datano data24 to 38 HRC
Other measurements
Elastic modulus, typical103 GPa2103 GPa113.8 GPa107 to 122 GPa91 GPa168 GPa82 GPa112 GPa103 GPa112 GPa15000 ksi
Beta transus1690 °F3913 °C995 °C966 °Cno datano data750 °C888 °C890 °Cno data800 °C
Mean coefficient of thermal expansion, 20 to 100 °C8.6 10-6/°C4no data8.6 10^-6 /°C9 10^-6 /°Cno datano datano data9.7 μm/(m·°C)9.54 10^-6/°C9.7 µm/m-°C9.7 ppm/K
Tensile strength, minimum (strip, sheet and plate)> 450 MPa6> 345 MPano data828 MPa> 620 MPa422 MPa1000 MPa> 240 MPa> 483 MPa> 345 MPa< 175 ksi
Yield strength, 0.2 % offset, minimum (strip, sheet and plate)> 380 MPa7> 275 MPa830 MPa759 MPa> 483 MPa326 MPa965 MPa> 138 MPa> 345 MPa> 275 MPa< 186 ksi
Elongation, minimum (strip, sheet and plate)> 18 %8> 20 %10 %10 %> 15 %1.7 %7 %> 24 %> 18 %> 20 %< 10 %
Tensile strength, typical593 MPa9> 345 MPano data828 MPa> 620 MPa422 MPa1000 MPa> 240 MPa> 483 MPa> 345 MPa< 175 ksi
Yield strength, 0.2 % offset, typical462 MPa10> 275 MPa830 MPa759 MPa> 483 MPa326 MPa965 MPa> 138 MPa> 345 MPa> 275 MPa< 186 ksi
Elongation, typical25 %11> 20 %10 %10 %> 15 %1.7 %7 %> 24 %> 18 %> 20 %< 10 %
Reduction of area, minimum> 35 %12> 35 %no data41.5 %no datano datano datano datano data> 30 %no data

Why choose it, and why not

Good for

  • Heat-exchanger matrix plates, where the grade is typically used (Alleima).
  • Forming and welding of sheet, strip and plate that needs more strength than Grade 2 (ASTM B265 Table 1; Smiths).
  • Aerospace sheet and coil to AMS 4900 (UPM, ATI).

Watch out for

  • Lower strength than Ti-6Al-4V: 450 MPa minimum tensile (see the Ti-6Al-4V profile).
  • No Grade 3 crevice or seawater test was found; the Titanium Industries page gives only general titanium statements.
  • Bending tighter than 2T (under 0.070 in) or 2.5T (0.070 to 0.187 in) is outside the ASTM bend-test radii.
  • Powder and swarf are a flammable-solid fire hazard (PubChem).
  • Composition limits differ between sources: Alleima prints lower Fe and O (nominal). ASTM B265 is used here.

CP titanium Grade 3 is the strongest of the commercially pure grades 1 to 3, with a 450 MPa minimum tensile strength and 18 % minimum elongation. It keeps good weldability and corrosion resistance in oxidising, neutral and mildly reducing media, including chlorides. It is not a structural alloy like Ti-6Al-4V, and the sources read give no Grade 3 crevice or seawater test.

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.

Other names and standards
SystemCodes
UNSR50550
EN3.7055
ASTMB265 (strip, sheet and plate), B348 (bars and billets), F67 (bar, plate and sheet)
ASMESB-265 (plate, strip and sheet)
AMS4900 (plate, sheet and strip), 4921 (bar)
NameCP Grade 3
Trade nameATI 55, Ti Grade 3

Notes

The method, full conditions and any caveat for the numbered rows above.

Notes for the numbered rows
#MeasurementMethodConditionsCaveat
1DensityPrinted as 4.51 g/cc in the product description of the Smiths CP Grade 3 datasheet. The ATI page prints 0.163 lb/in3 (4.51 g/cm3) for all forms, and the UPM datasheet prints 4.512 g/cm3.form CP Grade 3 product (datasheet product range)condition not statedunit in source g/cc—
2Elastic modulus, typicalPrinted as typical 103 GPa in the Mechanical Properties table of the Smiths datasheet. The UPM datasheet prints 15.2 to 17.4 Msi, which is not converted here.form CP Grade 3 product (datasheet product range)basis typical, not a minimumloading not stated—
3Beta transusPrinted as 1690 under the T (°F) column of the Physical Properties table of the UPM datasheet. The table prints no Celsius value, so none is given. beta_transus is not in the canonical list (see gaps).form sheet and coil (AMS 4900 datasheet)condition not stated—
4Mean coefficient of thermal expansion, 20 to 100 °CPrinted as 8.6x10-6 m/m°C for 20 to 100 °C in the Physical Properties table of the UPM datasheet, beside 4.8x10-6 in/in°F. The 20 to 300 °C and 20 to 500 °C rows (9.5 and 9.7) are not recorded.temperature 20 to 100 °C (printed 68 to 212 °F)basis mean coefficientunit in source m m-1 °C-1—
5Thermal conductivityPrinted as 151.2 Btu-in/hr ft2-F in the Physical Properties table of the UPM datasheet. No SI value is printed; the importer converts from the printed unit.temperature not stated (table dash)unit in source Btu-in/hr ft2- °F—
6Tensile strength, minimum (strip, sheet and plate)Minimum in Table 1 (Tensile Requirements) of the ASTM B265-08b copy, Grade 3 row, with 65 ksi printed beside 450 MPa. The ATI page prints the same 65 ksi and 450 MPa minimum for all forms.form strip, sheet and plate (ASTM B265 product)condition as specified for Grade 3 in ASTM B265-08b Table 1minimum yes—
7Yield strength, 0.2 % offset, minimum (strip, sheet and plate)Minimum in Table 1 of the ASTM B265-08b copy, Grade 3 row, with 55 ksi printed beside 380 MPa. The maximum of 80 ksi (550 MPa) in the same row is not recorded.form strip, sheet and plate (ASTM B265 product)offset 0.2 %minimum yes—
8Elongation, minimum (strip, sheet and plate)Minimum elongation in Table 1 of the ASTM B265-08b copy, Grade 3 row.form strip, sheet and plate (ASTM B265 product)gauge 2 in or 50 mmminimum yes—
9Tensile strength, typicalPrinted as typical 593 MPa in the UTS row of the Smiths datasheet mechanical properties table. The Smiths minimum of 448 MPa is not used; the ASTM minimum of 450 MPa is recorded instead.form CP Grade 3 product (datasheet product range)basis typical, not a minimum—
10Yield strength, 0.2 % offset, typicalPrinted as typical 462 MPa in the 0.2% PS row of the Smiths datasheet, and again in its product description. The Smiths minimum of 379 MPa is not used; the ASTM minimum of 380 MPa is recorded instead.form CP Grade 3 product (datasheet product range)offset 0.2 %basis typical, not a minimum—
11Elongation, typicalPrinted in the Elongation on 2 in row, typical column, of the Smiths CP Grade 3 datasheet.form CP Grade 3 product (datasheet product range)gauge 2 inbasis typical, not a minimum—
12Reduction of area, minimumPrinted in the Mechanical Properties table of the Smiths CP Grade 3 datasheet. reduction_of_area is not in the canonical list, so a snake_case name is used (see gaps).form CP Grade 3 product (datasheet product range)condition minimum as printed; no separate condition givenminimum yes—
13Charpy V-notch impact, minimumPrinted in the Mechanical Properties table of the Smiths CP Grade 3 datasheet. impact_energy is a snake_case name (see gaps).form CP Grade 3 product (datasheet product range)test Charpy V-notchminimum yes—
14Hardness, typicalPrinted as typical 200 HV in the Hardness HV row of the Smiths datasheet mechanical properties table. hardness is a snake_case name (see gaps).form CP Grade 3 product (datasheet product range)basis typical—
15Hardness, maximum (bar and billet)Printed as 90 HRB max. in the Properties list of the ATI page, for bar and billet only. The page gives no hardness value for plate, sheet or strip.form bar and billet only (ATI page)condition as supplied; no separate condition given—

Corrosion and compatibility

What happens when it meets other materials and environments.

Corrosion and compatibility
EnvironmentConcernWhat happens
Oxidising, neutral and mildly reducing media, including chlorides low High corrosion resistance in oxidising, neutral and mildly reducing media, including chlorides.1
Seawater and common salt solutions, pH 3 to 12 (general statement for titanium alloys) low General statement for titanium alloys: resists common salt solutions and chlorides from pH 3 to 12.2
Chloride stress corrosion (general statement for titanium) low General statement: titanium does not show the same chloride stress-corrosion susceptibility as stainless steel.3
Corrosion details
#EnvironmentDetailsTest conditions
1 Oxidising, neutral and mildly reducing media, including chlorides Smiths says the grade offers high corrosion resistance in oxidising, neutral and mildly reducing media, including chlorides. The datasheet prints no test conditions. basis manufacturer statement; no test conditions printedform CP Grade 3 product (Smiths datasheet)
2 Seawater and common salt solutions, pH 3 to 12 (general statement for titanium alloys) Titanium Industries says titanium alloys are expected to resist common salt solutions, chlorides and other listed solutions that have a pH range of 3 to 12. The page gives no statement specific to Grade 3 or to commercially pure titanium. basis general statement for titanium alloys; no Grade 3 testpH 3 to 12
3 Chloride stress corrosion (general statement for titanium) Titanium Industries says titanium does not demonstrate the same susceptibility to stress corrosion from chlorides as stainless steel. The statement is for titanium in general, not a Grade 3 test. basis general statement for titanium; 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 solid metal is not hazard-classed in the sources read. PubChem gives titanium a flammable-solid classification (H228), which applies to powder and swarf.

Solid metal
Sheet, strip, plate, bar and tube are covered by the Smiths datasheet and the ATI page, which list no hazard classification.
Powder and swarf
PubChem gives H228 (flammable solid) from aggregated reports, and reports 606 of 808 company reports as not meeting GHS hazard criteria. Treat powder and swarf as a fire hazard.

Test details
The original wording and numbers from the sources, for readers who want them.

Failure risks

Failure risks
FailureTrigger and consequence
Bending tighter than the specified radiusmoderate severityBending thin sheet or strip tighter than 2T (under 0.070 in) or tighter than 2.5T (0.070 to 0.187 in)ASTM B265 Table 1 sets the bend-test radii for Grade 3. The standard prints no failure data for tighter bends.
Use in media outside the stated rangemoderate severityStrongly reducing media (outside oxidising, neutral and mildly reducing media)Smiths rates corrosion resistance only for oxidising, neutral and mildly reducing media, including chlorides. It prints no data for strongly reducing media.

Handling and storage

  • Weldability is excellent. Specified bend radius is 2.0 times thickness for sections under 0.070 in and 2.5 times above that. Welded bend radius is 3.0 times thickness at minimum.
  • ASTM B265 bend-test radii for Grade 3 are 2T for thickness under 0.070 in and 2.5T for 0.070 to 0.187 in.

Supply and geography

How common the raw materials are and where they come from.

Titanium sponge (feedstock for titanium mill products)

Top producers (2025)
China 70.3%, Japan 14.3%, Russia 6.8%, Kazakhstan 4.3%, Saudi Arabia 3.2%