Titanium Grade C-9
ASTM B367 Grade C-9
A moderate-strength alpha-beta titanium casting alloy offering a balance between the CP grades and the higher-strength C-5 alloy, commonly added to standard casting catalogs for mid-strength net-shape parts.
Reference datasheet — Grade C-9 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 ANNEAL condition
Grade C-9 tempers and conditions
Grade C-9 is supplied in 5 conditions, soft to hard. ANNEAL is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Lowest-cost condition for non-critical, low-stress parts where internal porosity is acceptable. | 520 | 630 | 8 | 23 HRC | — |
Stress relieved | Choose when only casting/weld-repair residual stresses must be removed with minimal property change. | 530 | 640 | 9 | 24 HRC | 1.4 % IACS |
ANNEALDefault Annealed | Standard stocked condition: relieves casting stresses and stabilises properties to the ASTM B367 C-9 minima. | 550 | 655 | 10 | 25 HRC | — |
HIP + Annealed | Best overall combination of soundness, ductility and dimensional stability for aerospace/medical cast hardware. | 555 | 665 | 13 | 24 HRC | — |
Hot isostatic pressed | Specify for fatigue- or fracture-critical castings: closes internal gas/shrink porosity and lifts ductility and fatigue life. | 560 | 670 | 12 | 25 HRC | — |
What is Grade C-9?
A moderate-strength alpha-beta titanium casting alloy offering a balance between the CP grades and the higher-strength C-5 alloy, commonly added to standard casting catalogs for mid-strength net-shape parts. Grade C-9 has a density of 4.48 g/cm³ (0.162 lb/in³), lighter than 71% of titanium grades. It melts at 1,620°C (2,948 °F). Grade C-9 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 55% of titanium grades. Elongation at break is 10% and the elastic modulus is 100 GPa (14.5 Msi).
What is Grade C-9 used for?
- hydraulic tubing fittings
- aerospace secondary structure castings
- sporting goods castings
Limitations
- Limited ductility — 10%, worse than 93% of titanium grades
Grade C-9 properties
Typical room-temperature values for Grade C-9-ANNEAL; bars are the position among titanium grades.
Physical3
Grade C-9 has a density of 4.48 g/cm³ (0.162 lb/in³), lighter than 71% of titanium grades. It melts at 1,620°C (2,948 °F).
Mechanical16
Grade C-9 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 55% of titanium grades. Elongation at break is 10% and the elastic modulus is 100 GPa (14.5 Msi).
Thermal6
Grade C-9 is rated for continuous service to 300°C (572 °F). It conducts heat at 7.6 W/m·K (4.39 BTU/hr·ft·°F), worse than 59% of titanium grades. Thermal expansion is 9.4 µm/m·K (5.22 µin/in·°F).
Electrical3
Grade C-9 conducts electricity at 1.4 % IACS, better than 53% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), worse than 63% of titanium grades.
Sustainability4
Producing a kilogram of Grade C-9 takes about 680 MJ of energy and emits 45 kg of CO₂ — more than 51% of titanium grades. Typical recycled content is 30%.
Manufacturability8
Grade C-9's machinability is poor (25/100, better than 53% of titanium grades); weldability very good (80/100); formability poor (25/100).
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-9 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Grade C-9
Is Grade C-9 easy to machine?
Machine with sharp uncoated-carbide or PVD carbide tools at low surface speed (25–45 m/min), heavy feed, rigid setup and flood coolant; avoid dwelling to prevent work hardening and titanium fire risk from fine chips.
Can Grade C-9 be welded?
Readily GTAW/EBW/plasma welded and weld-repaired with matching Gr 9 filler under full argon trailing/backing shielding or in a chamber; keep weld-zone oxygen/hydrogen low and post-weld stress relieve.
Can Grade C-9 be formed, bent or molded?
Supplied as a net-shape investment or rammed-graphite casting from vacuum arc/induction skull melting; cold forming is not applicable, minor straightening only when hot (>600 °C in inert atmosphere).
Grade C-9 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 |
|---|---|---|
| Alalpha stabiliser | 2.5 – 3.5 | 3 |
| Vbeta stabiliser | 2 – 3 | 2.5 |
| Fe | ≤ 0.25 | 0.15 |
| Ointerstitial, controls strength | ≤ 0.15 | 0.12 |
| C | ≤ 0.08 | 0.03 |
| N | ≤ 0.05 | 0.02 |
| Hmax for castings | ≤ 0.02 | 0.01 |
| Residuals (each)total residuals max 0.4 % | ≤ 0.1 | |
| Ti | balance |
What surface finishes work on Grade C-9?
Chemically mill/pickle in HNO₃-HF to remove alpha case and mold reaction layer, then grit blast, polish or colour/hard anodise; avoid iron contamination from steel abrasives.
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-9 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B367 Grade C-9
How much does Grade C-9 cost?
Grade C-9 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-9 — frequently asked
What is Grade C-9 used for?
Grade C-9 is typically used for hydraulic tubing fittings, aerospace secondary structure castings and sporting goods castings. In short: mid-strength cast titanium; between CP and C-5; net-shape pressure fittings.
What is the yield strength of Grade C-9?
Grade C-9 has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 655 MPa (95 ksi) — weaker than 55% of titanium grades. Strength varies by condition: see the 5 listed tempers.
Is Grade C-9 easy to machine?
Not especially — machinability is rated poor (25/100, better than 53% of titanium grades). Machine with sharp uncoated-carbide or PVD carbide tools at low surface speed (25–45 m/min), heavy feed, rigid setup and flood coolant; avoid dwelling to prevent work hardening and titanium fire risk from fine chips.
Can Grade C-9 be welded?
Yes — weldability is rated very good (80/100). Readily GTAW/EBW/plasma welded and weld-repaired with matching Gr 9 filler under full argon trailing/backing shielding or in a chamber; keep weld-zone oxygen/hydrogen low and post-weld stress relieve.
What surface finishes work on Grade C-9?
Chemically mill/pickle in HNO₃-HF to remove alpha case and mold reaction layer, then grit blast, polish or colour/hard anodise; avoid iron contamination from steel abrasives.
Can Grade C-9 be formed, bent or molded?
Supplied as a net-shape investment or rammed-graphite casting from vacuum arc/induction skull melting; cold forming is not applicable, minor straightening only when hot (>600 °C in inert atmosphere).
What is the maximum service temperature of Grade C-9?
Grade C-9 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Grade C-9 ANNEAL and Grade C-9-F?
ANNEAL is the default condition — standard stocked condition: relieves casting stresses and stabilises properties to the ASTM B367 C-9 minima. F: lowest-cost condition for non-critical, low-stress parts where internal porosity is acceptable. Yield strength is 550 MPa in ANNEAL versus 520 MPa in F.
How much does Grade C-9 cost?
Grade C-9 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)
- ASTM B338 / B348 (wrought Grade 9 Ti-3Al-2.5V chemistry and properties) — ASTM International (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (Titanium) — ASM International (2005)
- Ti-3Al-2.5V (Grade 9) alloy datasheet — Sandvik / TIMET (2020)
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.