Titanium Grade C-5
ASTM B367 Grade C-5
Grade C-5 (UNS R56400) is the cast form of Ti-6Al-4V, an alpha-beta alloy strengthened by aluminium and vanadium and covered by ASTM B367.
Reference datasheet — Grade C-5 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the HIP condition
Grade C-5 tempers and conditions
Grade C-5 is supplied in 4 conditions, soft to hard. HIP is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Lowest-cost condition for non-critical industrial castings where internal microporosity is acceptable. | 840 | 910 | 7 | 34 HRC | 1 % IACS |
Annealed | Stress-relieved/annealed castings meeting ASTM B367 C-5 minimums without HIP; general industrial and marine hardware. | 855 | 925 | 8 | 35 HRC | 1 % IACS |
HIPDefault Hot isostatic pressed | Default aerospace/medical condition: HIP closes casting porosity, raising ductility and fatigue life to near-wrought levels. | 865 | 940 | 10 | 35 HRC | — |
Solution treated and aged | Choose when maximum strength is needed in thin/uniform sections; ductility and toughness drop and response is section-size limited. | 970 | 1,070 | 6 | 38 HRC | — |
Supply forms, finishes and certifications
Ways Grade C-5 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
BA | Beta annealed (above beta transus, ~1035 °C) plus HIP | Surface finish |
What is Grade C-5?
Grade C-5 (UNS R56400) is the cast form of Ti-6Al-4V, an alpha-beta alloy strengthened by aluminium and vanadium and covered by ASTM B367. It is the default choice when a complex net-shape investment casting must approach wrought strength — 865 MPa yield, 940 MPa tensile, 10 % elongation and 330 HB (35 HRC) — for airframe brackets and engine hardware. Ductility and machinability (score 20) are the trade-offs, and HIP plus chemical milling are normally required, which raises cost; where corrosion rather than strength drives the design, C-2 or C-3 are cheaper and easier to cut. Grade C-5 has a density of 4.43 g/cm³ (0.16 lb/in³), lighter than 89% of titanium grades. It melts at 1,604°C (2,919 °F). Grade C-5 has a yield strength of 865 MPa (125 ksi) and a tensile strength of 940 MPa (136 ksi) — stronger than 74% of titanium grades. Elongation at break is 10% and the elastic modulus is 112 GPa (16.2 Msi).
What is Grade C-5 used for?
- aerospace structural castings
- turbine engine components
- airframe brackets
- high-performance sporting goods
Advantages
- Tough — resists crack growth — 85 MPa·√m (77.4 ksi·√in), better than 91% of titanium grades
- High service temperature — 400°C (752 °F), better than 78% of titanium grades
Limitations
- Limited ductility — 10%, worse than 93% of titanium grades
- Limited formability — 15/100, worse than 93% of titanium grades
- Low electrical conductivity — 1 % IACS, worse than 89% of titanium grades
- Poor heat conductor — 6.8 W/m·K (3.93 BTU/hr·ft·°F), worse than 86% of titanium grades
- Difficult to weld — 65/100, worse than 77% of titanium grades
Grade C-5 properties
Typical room-temperature values for Grade C-5-HIP; bars are the position among titanium grades.
Physical3
Grade C-5 has a density of 4.43 g/cm³ (0.16 lb/in³), lighter than 89% of titanium grades. It melts at 1,604°C (2,919 °F).
Mechanical16
Grade C-5 has a yield strength of 865 MPa (125 ksi) and a tensile strength of 940 MPa (136 ksi) — stronger than 74% of titanium grades. Elongation at break is 10% and the elastic modulus is 112 GPa (16.2 Msi).
Thermal6
Grade C-5 is rated for continuous service to 400°C (752 °F). It conducts heat at 6.8 W/m·K (3.93 BTU/hr·ft·°F), worse than 86% of titanium grades. Thermal expansion is 8.7 µm/m·K (4.83 µin/in·°F).
Electrical3
Grade C-5 conducts electricity at 1 % IACS, worse than 89% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), worse than 77% of titanium grades.
Sustainability4
Producing a kilogram of Grade C-5 takes about 660 MJ of energy and emits 44 kg of CO₂ — less than 57% of titanium grades. Typical recycled content is 40%.
Manufacturability8
Grade C-5's machinability is poor (20/100, worse than 68% of titanium grades); weldability good (65/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the titanium family
Yield strength against density for every titanium grade FabDigit runs. Grade C-5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Grade C-5
Is Grade C-5 easy to machine?
Machine like wrought Ti-6Al-4V: rigid setups, sharp uncoated-carbide or PVD tools, 30–60 m/min, heavy positive-pressure flood coolant, and remove the hard oxygen-rich alpha case (chem-mill) before finish cuts.
Can Grade C-5 be welded?
Readily GTAW/EBW/plasma welded and weld-repaired with matching filler under high-purity argon or in vacuum; back-purge, keep interstitials low, and stress-relieve or re-HIP after major repairs.
Can Grade C-5 be formed, bent or molded?
Supplied as investment/rammed-graphite castings from VAR or skull-melted stock; design generous fillets and 2.5–4 mm minimum walls, and expect HIP plus chemical milling to reach final dimensions.
Grade C-5 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.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Al | 5.5 – 6.75 | 6.1 |
| V | 3.5 – 4.5 | 4 |
| Fe | ≤ 0.4 | 0.15 |
| Omax; many foundries hold ≤0.20 | ≤ 0.25 | 0.18 |
| C | ≤ 0.1 | 0.02 |
| N | ≤ 0.05 | 0.02 |
| H | ≤ 0.02 | 0.01 |
| Residuals (each)0.4 max total | ≤ 0.1 | |
| Ti | balance |
What surface finishes work on Grade C-5?
Chemical milling, abrasive/vibratory finishing, shot peening for fatigue, and Type II colour or Type III hard anodising per AMS 2488; avoid chlorinated cleaners and cadmium/mercury contact.
Surface treatments FabDigit runs on titanium parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Titanium Grade C-5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B367 Grade C-5
- Similar grades
- R56400
How much does Grade C-5 cost?
Grade C-5 is a high-cost titanium ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Grade C-5 — frequently asked
What is Grade C-5 used for?
Grade C-5 is typically used for aerospace structural castings, turbine engine components, airframe brackets and high-performance sporting goods. In short: near-wrought Ti-6Al-4V strength; highest-strength B367 casting; hardest to machine.
What is the yield strength of Grade C-5?
Grade C-5 has a typical yield strength of 865 MPa (125 ksi) and a tensile strength of 940 MPa (136 ksi) — stronger than 74% of titanium grades. Strength varies by condition: see the 4 listed tempers.
Is Grade C-5 easy to machine?
Not especially — machinability is rated poor (20/100, worse than 68% of titanium grades). Machine like wrought Ti-6Al-4V: rigid setups, sharp uncoated-carbide or PVD tools, 30–60 m/min, heavy positive-pressure flood coolant, and remove the hard oxygen-rich alpha case (chem-mill) before finish cuts.
Can Grade C-5 be welded?
Yes — weldability is rated good (65/100). Readily GTAW/EBW/plasma welded and weld-repaired with matching filler under high-purity argon or in vacuum; back-purge, keep interstitials low, and stress-relieve or re-HIP after major repairs.
What surface finishes work on Grade C-5?
Chemical milling, abrasive/vibratory finishing, shot peening for fatigue, and Type II colour or Type III hard anodising per AMS 2488; avoid chlorinated cleaners and cadmium/mercury contact.
Can Grade C-5 be formed, bent or molded?
Supplied as investment/rammed-graphite castings from VAR or skull-melted stock; design generous fillets and 2.5–4 mm minimum walls, and expect HIP plus chemical milling to reach final dimensions.
What is the maximum service temperature of Grade C-5?
Grade C-5 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Grade C-5-HIP and Grade C-5-STA?
HIP is the default condition — default aerospace/medical condition: HIP closes casting porosity, raising ductility and fatigue life to near-wrought levels. STA: choose when maximum strength is needed in thin/uniform sections; ductility and toughness drop and response is section-size limited. Yield strength is 865 MPa in HIP versus 970 MPa in STA.
How much does Grade C-5 cost?
Grade C-5 is a high-cost titanium ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B367 Standard Specification for Titanium and Titanium Alloy Castings — ASTM International (2022)
- AMS 4992 / AMS 2488 (cast Ti-6Al-4V, titanium anodising) — SAE International (2020)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 15 — Casting (Titanium investment casting) — ASM International (2008)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- MMPDS-18 titanium alloy chapter — Battelle/FAA (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.