Titanium Grade C-9-SR (Stress relieved)
Heat-treated state
ASTM B367 Grade C-9
Choose when only casting/weld-repair residual stresses must be removed with minimal property change.
Values for the SR condition
Other Grade C-9 tempers and conditions
Grade C-9 is listed in 5 conditions; see the grade overview at Grade C-9.
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 | — |
SRThis page 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-SR?
Grade C-9-SR is Grade C-9 heat treated to SR — choose when only casting/weld-repair residual stresses must be removed with minimal property change. Grade C-9-SR has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 59% of titanium grades. Elongation at break is 9% and the elastic modulus is 100 GPa (14.5 Msi). Grade C-9-SR 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). ANNEAL is the default condition FabDigit quotes; SR is available on request or by drawing note.
Limitations
- Limited ductility — 9%, worse than 97% of titanium grades
Grade C-9-SR properties
Typical room-temperature values for Grade C-9-SR; 23 are specific to this condition. Other listed values are Grade C-9 reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
Grade C-9-SR 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-SR has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 59% of titanium grades. Elongation at break is 9% and the elastic modulus is 100 GPa (14.5 Msi).
Thermal6
Grade C-9-SR 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-SR 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-SR 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-SR's machinability is poor (26/100, better than 57% of titanium grades); weldability very good (80/100); formability poor (27/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Grade C-9-SR
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).
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.
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 | — |
Grade C-9-SR — frequently asked
What is Grade C-9-SR used for?
Grade C-9-SR 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-SR?
Grade C-9-SR has a typical yield strength of 530 MPa (76.9 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 59% of titanium grades. Strength varies by condition: see the 5 listed tempers.
Is Grade C-9-SR easy to machine?
Not especially — machinability is rated poor (26/100, better than 57% 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-SR 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-SR?
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-SR 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-SR?
Grade C-9-SR 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.