Titanium Grade C-5-AC (Spheroidize annealed)
Heat-treated state
ASTM B367 Grade C-5
Lowest-cost condition for non-critical industrial castings where internal microporosity is acceptable.
Values for the AC condition
Other Grade C-5 tempers and conditions
Grade C-5 is listed in 4 conditions; see the grade overview at Grade C-5.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ACThis page 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 | — |
What is Grade C-5-AC?
Grade C-5-AC is Grade C-5 heat treated to AC — lowest-cost condition for non-critical industrial castings where internal microporosity is acceptable. Grade C-5-AC has a yield strength of 840 MPa (122 ksi) and a tensile strength of 910 MPa (132 ksi) — stronger than 63% of titanium grades. Elongation at break is 7% and the elastic modulus is 112 GPa (16.2 Msi). Grade C-5-AC 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). HIP is the default condition FabDigit quotes; AC is available on request or by drawing note.
Limitations
- Limited ductility — 7%, worse than 100% of titanium grades
- Limited formability — 10/100, worse than 99% of titanium grades
- Low electrical conductivity — 1 % IACS, worse than 89% of titanium grades
- Difficult to weld — 55/100, worse than 87% of titanium grades
- Poor heat conductor — 6.8 W/m·K (3.93 BTU/hr·ft·°F), worse than 86% of titanium grades
Grade C-5-AC properties
Typical room-temperature values for Grade C-5-AC; 22 are specific to this condition. Other listed values are Grade C-5 reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
Grade C-5-AC 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-AC has a yield strength of 840 MPa (122 ksi) and a tensile strength of 910 MPa (132 ksi) — stronger than 63% of titanium grades. Elongation at break is 7% and the elastic modulus is 112 GPa (16.2 Msi).
Thermal6
Grade C-5-AC is rated for continuous service to 350°C (662 °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-AC conducts electricity at 1 % IACS, worse than 89% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (86/100), worse than 86% of titanium grades.
Sustainability4
Producing a kilogram of Grade C-5-AC 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-AC's machinability is poor (18/100, worse than 83% of titanium grades); weldability good (55/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Grade C-5-AC
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.
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.
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 | — |
Grade C-5-AC — frequently asked
What is Grade C-5-AC used for?
Grade C-5-AC 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-AC?
Grade C-5-AC has a typical yield strength of 840 MPa (122 ksi) and a tensile strength of 910 MPa (132 ksi) — stronger than 63% of titanium grades. Strength varies by condition: see the 4 listed tempers.
Is Grade C-5-AC easy to machine?
Not especially — machinability is rated poor (18/100, worse than 83% 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-AC be welded?
Yes — weldability is rated good (55/100). 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-AC?
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-AC 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-AC?
Grade C-5-AC is rated for continuous use to about 350°C (662 °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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.