Titanium Grade C-2-SR (Stress relieved)
Heat-treated state
ASTM B367 Grade C-2
Choose when casting or weld-repair residual stress must be removed before machining or service to minimise distortion and SCC risk.
Values for the SR condition
Other Grade C-2 tempers and conditions
Grade C-2 is listed in 4 conditions; see the grade overview at Grade C-2.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HIP + stress relieve/anneal | Use for large, thick-section or weld-repaired castings needing both porosity closure and low residual stress before final machining. | 360 | 460 | 22 | 190 HB | 3.1 % IACS |
SRThis page Stress relieved | Choose when casting or weld-repair residual stress must be removed before machining or service to minimise distortion and SCC risk. | 365 | 465 | 18 | 195 HB | 3.1 % IACS |
Hot isostatic pressed | Pick for pressure-containing or fatigue-loaded castings — HIP closes shrinkage porosity and raises ductility and fatigue life. | 370 | 470 | 21 | 195 HB | — |
FDefault As fabricated | Standard supply condition for corrosion-service castings where internal porosity is acceptable (non-pressure-critical or NDT-verified parts). | 385 | 480 | 16 | 205 HB | — |
What is Grade C-2-SR?
Grade C-2-SR is Grade C-2 heat treated to SR — choose when casting or weld-repair residual stress must be removed before machining or service to minimise distortion and SCC risk. Grade C-2-SR has a yield strength of 365 MPa (52.9 ksi) and a tensile strength of 465 MPa (67.4 ksi) — weaker than 76% of titanium grades. Elongation at break is 18% and the elastic modulus is 103 GPa (14.9 Msi). Grade C-2-SR has a density of 4.51 g/cm³ (0.163 lb/in³), heavier than 57% of titanium grades. It melts at 1,660°C (3,020 °F). F is the default condition FabDigit quotes; SR is available on request or by drawing note.
Advantages
- Easy to machine — 38/100, better than 85% of titanium grades
- High electrical conductivity — 3.1 % IACS, better than 75% of titanium grades
Limitations
- Low strength — 365 MPa (52.9 ksi), worse than 76% of titanium grades
Grade C-2-SR properties
Typical room-temperature values for Grade C-2-SR; 22 are specific to this condition. Other listed values are Grade C-2 reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
Grade C-2-SR has a density of 4.51 g/cm³ (0.163 lb/in³), heavier than 57% of titanium grades. It melts at 1,660°C (3,020 °F).
Mechanical16
Grade C-2-SR has a yield strength of 365 MPa (52.9 ksi) and a tensile strength of 465 MPa (67.4 ksi) — weaker than 76% of titanium grades. Elongation at break is 18% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
Grade C-2-SR is rated for continuous service to 315°C (599 °F). It conducts heat at 16.4 W/m·K (9.48 BTU/hr·ft·°F), better than 71% of titanium grades. Thermal expansion is 8.6 µm/m·K (4.78 µin/in·°F).
Electrical3
Grade C-2-SR conducts electricity at 3.1 % IACS, better than 75% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (93/100), better than 72% of titanium grades.
Sustainability4
Producing a kilogram of Grade C-2-SR takes about 700 MJ of energy and emits 46 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 30%.
Manufacturability8
Grade C-2-SR's machinability is fair (38/100, better than 85% of titanium grades); weldability excellent (88/100); formability poor (28/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Grade C-2-SR
Is Grade C-2 easy to machine?
Machine with sharp, positive-rake carbide, low surface speed (30–60 m/min), heavy flood coolant and constant feed to avoid work hardening, galling and chip fires; remove hard α-case with chem-milling before finish cuts.
Can Grade C-2 be welded?
Readily GTAW/EBW/plasma welded with matching CP-Ti filler under full argon/helium shielding including trailing shield and back purge — weld area must be bright silver; weld repair of castings is permitted by ASTM B367 with subsequent stress relief.
Can Grade C-2 be formed, bent or molded?
Supplied as a casting: vacuum induction/skull melting into rammed graphite or ceramic shell moulds, centrifugal pouring for thin sections; allow generous machining stock for α-case removal and expect HIP for pressure-rated parts.
What surface finishes work on Grade C-2?
Grit blast plus chemical (HNO₃/HF) pickling to strip α-case, then passivate; anodize per AMS 2488/2487 for colour or wear, or leave bare — the natural oxide already gives full corrosion protection.
Grade C-2 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 |
|---|---|---|
| Nmax per ASTM B367 Grade C-2 | ≤ 0.05 | 0.02 |
| C | ≤ 0.1 | 0.03 |
| Hvacuum-melted castings typically well below max | ≤ 0.02 | 0.01 |
| Fe | ≤ 0.25 | 0.15 |
| Ooxygen controls strength; surface α-case must be removed | ≤ 0.25 | 0.2 |
| residuals eacheach other element | ≤ 0.1 | — |
| residuals totalsum of other elements | ≤ 0.4 | — |
| Ti | balance | — |
Grade C-2-SR — frequently asked
What is Grade C-2-SR used for?
Grade C-2-SR is typically used for marine hardware castings, chemical process valve bodies, pump housings and medical instrument castings. In short: most ductile CP-Ti casting; weld-repairable per B367; corrosion-first cast grade.
What is the yield strength of Grade C-2-SR?
Grade C-2-SR has a typical yield strength of 365 MPa (52.9 ksi) and a tensile strength of 465 MPa (67.4 ksi) — weaker than 76% of titanium grades. Strength varies by condition: see the 4 listed tempers.
Is Grade C-2-SR easy to machine?
Not especially — machinability is rated fair (38/100, better than 85% of titanium grades). Machine with sharp, positive-rake carbide, low surface speed (30–60 m/min), heavy flood coolant and constant feed to avoid work hardening, galling and chip fires; remove hard α-case with chem-milling before finish cuts.
Can Grade C-2-SR be welded?
Yes — weldability is rated excellent (88/100). Readily GTAW/EBW/plasma welded with matching CP-Ti filler under full argon/helium shielding including trailing shield and back purge — weld area must be bright silver; weld repair of castings is permitted by ASTM B367 with subsequent stress relief.
What surface finishes work on Grade C-2-SR?
Grit blast plus chemical (HNO₃/HF) pickling to strip α-case, then passivate; anodize per AMS 2488/2487 for colour or wear, or leave bare — the natural oxide already gives full corrosion protection.
Can Grade C-2-SR be formed, bent or molded?
Supplied as a casting: vacuum induction/skull melting into rammed graphite or ceramic shell moulds, centrifugal pouring for thin sections; allow generous machining stock for α-case removal and expect HIP for pressure-rated parts.
What is the maximum service temperature of Grade C-2-SR?
Grade C-2-SR is rated for continuous use to about 315°C (599 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Grade C-2-F and Grade C-2-SR?
F is the default condition — standard supply condition for corrosion-service castings where internal porosity is acceptable (non-pressure-critical or NDT-verified parts). SR: choose when casting or weld-repair residual stress must be removed before machining or service to minimise distortion and SCC risk. Yield strength is 385 MPa in F versus 365 MPa in SR.
Sources
- ASTM B367 Standard Specification for Titanium and Titanium Alloy Castings — ASTM International (2022)
- ASTM B348 / ASTM F67 (wrought CP-Ti grade comparison) — ASTM International (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Titanium) — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (Titanium) — ASM International (2005)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- GB/T 15073 / GB/T 6614 — SAC (2014)
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.