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Titanium Grade C-6-F (As fabricated)

Temper

ASTM B367 Grade C-6

Baseline condition for non-critical castings where porosity from solidification is acceptable.

High cost $$$$

Values for the F condition

Other Grade C-6 tempers and conditions

Grade C-6 is listed in 5 conditions; see the grade overview at Grade C-6.

Compare all 5 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Extra-low-interstitial casting variant (O ≤ 0.12 %), HIP + annealed
Specified for liquid-hydrogen/oxygen and other cryogenic hardware where toughness down to −253 °C matters more than room-temperature strength.7207901427 HRC1.1 % IACS
FThis page
As fabricated
Baseline condition for non-critical castings where porosity from solidification is acceptable.790850831 HRC—
Annealed
Pick when residual casting/welding stresses must be removed and ductility made uniform.7958551030 HRC1.1 % IACS
HIP+ANNDefault
HIP + Annealed
Standard aerospace/cryogenic casting delivery condition: densified, stress-free and dimensionally stable.8008601231 HRC—
Hot isostatic pressed
Choose for fatigue- or fracture-critical castings; HIP closes internal shrinkage porosity.8058701231 HRC1.1 % IACS

What is Grade C-6-F?

Grade C-6-F is Grade C-6 in the F temper — baseline condition for non-critical castings where porosity from solidification is acceptable. Grade C-6-F has a yield strength of 790 MPa (115 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 55% of titanium grades. Elongation at break is 8% and the elastic modulus is 110 GPa (16 Msi). Grade C-6-F has a density of 4.48 g/cm³ (0.162 lb/in³), lighter than 71% of titanium grades. It melts at 1,540°C (2,804 °F). HIP+ANN is the default condition FabDigit quotes; F is available on request or by drawing note.

Advantages

  • High service temperature — 480°C (896 °F), better than 90% of titanium grades

Limitations

  • Limited ductility — 8%, worse than 99% of titanium grades
  • Hard to polish — 60/100, worse than 97% of titanium grades
  • Limited formability — 15/100, worse than 93% of titanium grades

Grade C-6-F properties

Typical room-temperature values for Grade C-6-F; 10 are specific to this condition. Other listed values are Grade C-6 reference data and may not represent this condition. Bars are the position among titanium grades.

Physical3

Grade C-6-F has a density of 4.48 g/cm³ (0.162 lb/in³), lighter than 71% of titanium grades. It melts at 1,540°C (2,804 °F).

Density4.48 g/cm³0.16 lb/in³
Melting Point (Solidus)1,540°C2,804 °F
Liquidus Temperature1,620°C2,948 °F

Mechanical16

Grade C-6-F has a yield strength of 790 MPa (115 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 55% of titanium grades. Elongation at break is 8% and the elastic modulus is 110 GPa (16 Msi).

Elastic (Young's) Modulus110 GPa16 Msi
Shear Modulus44 GPa6.4 Msi
Bulk Modulus110 GPa16 Msi
Poisson's Ratio0.31
Tensile Strength (Ultimate)850 MPa123 ksi
Yield Strength (0.2% offset)790 MPa115 ksi
Elongation at Break8%
Reduction in Area14%
Compressive Strength880 MPa128 ksi
Shear Strength590 MPa85.6 ksi
Fatigue Strength (Endurance Limit)370 MPa53.7 ksi
Fracture Toughness (K_IC)65 MPa·√m59.2 ksi·√in
Charpy V-Notch Impact (RT)25 J18.4 ft·lbf
Hardness, Brinell300 HB
Hardness, Rockwell C31 HRC
Hardness, Vickers315 HV

Thermal6

Grade C-6-F is rated for continuous service to 480°C (896 °F). It conducts heat at 7.8 W/m·K (4.51 BTU/hr·ft·°F), worse than 53% of titanium grades. Thermal expansion is 9.4 µm/m·K (5.22 µin/in·°F).

Thermal Conductivity7.8 W/m·K4.5 BTU/hr·ft·°F
Specific Heat Capacity500 J/kg·K0.12 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)9.4 µm/m·K5.2 µin/in·°F
Latent Heat of Fusion325 J/g140 BTU/lb
Max Service Temperature (continuous)480°C896 °F
Min Service Temperature-196°C-321 °F

Electrical3

Grade C-6-F conducts electricity at 1.1 % IACS, worse than 67% of titanium grades.

Electrical Conductivity1.1 % IACS
Electrical Resistivity1.57×10⁻⁶ Ω·m61.8 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is excellent (88/100), worse than 77% of titanium grades.

Galvanic Potential (seawater, vs SCE)-0.1 V
Corrosion ResistanceExcellent88/100
Chemical Resistance SummaryExcellent in seawater, wet chlorine, oxidising acids and most chlorides thanks to the TiO₂ film; attacked by HF, hot concentrated HCl/H₂SO₄, and risks hydrogen pick-up in reducing acids or cathodic conditions.

Sustainability4

Producing a kilogram of Grade C-6-F takes about 680 MJ of energy and emits 45 kg of CO₂ — more than 51% of titanium grades. Typical recycled content is 25%.

Embodied Energy (primary production)680 MJ/kg292,348 BTU/lb
Embodied Carbon (primary production)45 kg CO₂/kg
Embodied Water450 L/kg53.9 gal/lb
Typical Recycled Content25%

Manufacturability8

Grade C-6-F's machinability is poor (22/100, worse than 55% of titanium grades); weldability very good (80/100); formability poor (15/100).

MachinabilityPoor22/100
Machinability Rating (AISI 1212 = 100 %)22%
WeldabilityVery good80/100
Formability (cold)Poor15/100
CastabilityGood62/100
Brazeability / SolderabilityFair40/100
PolishabilityGood60/100
Anodizing Responsegood — Type II/III colour and wear anodising plus chemical conversion are routine; cast surfaces need alpha-case and investment-shell removal first

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Grade C-6-F

Is Grade C-6 easy to machine?

Machine like other alpha titanium: rigid setup, sharp uncoated-carbide or PVD tools, 25–45 m/min, heavy flood coolant, positive rake and no dwell — alpha case from casting must be removed by chem-mill/grinding before finish cuts.

Can Grade C-6 be welded?

Readily GTAW/EBW/laser welded with matching filler under full argon or vacuum trailing/backing shielding; keep O+N pickup low, weld colour must be bright silver, and post-weld stress relieve 540–650 °C.

Can Grade C-6 be formed, bent or molded?

Supplied as investment or rammed-graphite castings from vacuum-arc skull or induction melting; allow generous shrink (~1.5 %), HIP to close shrinkage porosity — cold forming of the casting is not practical.

What surface finishes work on Grade C-6?

Chemical mill or grit blast plus pickle to remove shell and alpha case, then anodise (Type II colour / AMS 2488 Type III), chemical convert or dry-film lubricate; avoid chloride-bearing marking inks before elevated-temperature service.

Grade C-6 chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

ElementSpec limit (wt %)Nominal
Alalpha stabiliser4 – 65
Sn2 – 32.5
Fe≤ 0.50.25
OELI variant ≤ 0.12 %≤ 0.20.15
C≤ 0.10.03
N≤ 0.050.02
H0.0150 % max on castings≤ 0.020.01
Residuals (each)total 0.40 max≤ 0.1—
Tibalance—

Grade C-6-F — frequently asked

What is Grade C-6-F used for?

Grade C-6-F is typically used for cryogenic tankage fittings, aerospace ducting castings and pressure vessel components. In short: alpha alloy, weldable; cryogenic to 480 °C; alternative to cast C-5.

What is the yield strength of Grade C-6-F?

Grade C-6-F has a typical yield strength of 790 MPa (115 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 55% of titanium grades. Strength varies by condition: see the 5 listed tempers.

Is Grade C-6-F easy to machine?

Not especially — machinability is rated poor (22/100, worse than 55% of titanium grades). Machine like other alpha titanium: rigid setup, sharp uncoated-carbide or PVD tools, 25–45 m/min, heavy flood coolant, positive rake and no dwell — alpha case from casting must be removed by chem-mill/grinding before finish cuts.

Can Grade C-6-F be welded?

Yes — weldability is rated very good (80/100). Readily GTAW/EBW/laser welded with matching filler under full argon or vacuum trailing/backing shielding; keep O+N pickup low, weld colour must be bright silver, and post-weld stress relieve 540–650 °C.

What surface finishes work on Grade C-6-F?

Chemical mill or grit blast plus pickle to remove shell and alpha case, then anodise (Type II colour / AMS 2488 Type III), chemical convert or dry-film lubricate; avoid chloride-bearing marking inks before elevated-temperature service.

Can Grade C-6-F be formed, bent or molded?

Supplied as investment or rammed-graphite castings from vacuum-arc skull or induction melting; allow generous shrink (~1.5 %), HIP to close shrinkage porosity — cold forming of the casting is not practical.

What is the maximum service temperature of Grade C-6-F?

Grade C-6-F is rated for continuous use to about 480°C (896 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between Grade C-6 HIP+ANN and Grade C-6-ELI?

HIP+ANN is the default condition — standard aerospace/cryogenic casting delivery condition: densified, stress-free and dimensionally stable. ELI: specified for liquid-hydrogen/oxygen and other cryogenic hardware where toughness down to −253 °C matters more than room-temperature strength. Yield strength is 800 MPa in HIP+ANN versus 720 MPa in ELI.

Sources

  1. ASTM B367 — Titanium and Titanium Alloy Castings — ASTM International (2022)
  2. ASTM B265 — Titanium and Titanium Alloy Strip, Sheet and Plate (Grade 6) — ASTM International (2020)
  3. ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
  4. Materials Properties Handbook: Titanium Alloys — ASM International (1994)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.