Titanium Grade C-3-SR (Stress relieved)
Heat-treated state
ASTM B367 Grade C-3
Use after heavy weld repair or rough machining to remove residual stress and stabilise dimensions.
Values for the SR condition
Other Grade C-3 tempers and conditions
Grade C-3 is listed in 4 conditions; see the grade overview at Grade C-3.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SRThis page Stress relieved | Use after heavy weld repair or rough machining to remove residual stress and stabilise dimensions. | 505 | 605 | 16 | 22 HRC | 3.1 % IACS |
HIP + anneal | Best ductility/toughness combination for critical aerospace or implant-grade CP-Ti castings. | 510 | 615 | 20 | 22 HRC | 3.1 % IACS |
FDefault As fabricated | Standard supply condition for non-critical corrosion hardware where residual microporosity is acceptable. | 520 | 620 | 14 | 250 HB | — |
Hot isostatic pressed | Choose for fatigue-loaded, pressure-boundary or medical castings where internal porosity must be closed. | 525 | 630 | 18 | 245 HB | — |
What is Grade C-3-SR?
Grade C-3-SR is Grade C-3 heat treated to SR — use after heavy weld repair or rough machining to remove residual stress and stabilise dimensions. Grade C-3-SR has a yield strength of 505 MPa (73.2 ksi) and a tensile strength of 605 MPa (87.7 ksi) — weaker than 62% of titanium grades. Elongation at break is 16% and the elastic modulus is 104 GPa (15.1 Msi). Grade C-3-SR has a density of 4.51 g/cm³ (0.163 lb/in³), heavier than 57% of titanium grades. It melts at 1,650°C (3,002 °F). F is the default condition FabDigit quotes; SR is available on request or by drawing note.
Advantages
- Conducts heat well — 17.2 W/m·K (9.94 BTU/hr·ft·°F), better than 88% of titanium grades
- High service temperature — 400°C (752 °F), better than 78% of titanium grades
- High electrical conductivity — 3.1 % IACS, better than 75% of titanium grades
Grade C-3-SR properties
Typical room-temperature values for Grade C-3-SR; 23 are specific to this condition. Other listed values are Grade C-3 reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
Grade C-3-SR has a density of 4.51 g/cm³ (0.163 lb/in³), heavier than 57% of titanium grades. It melts at 1,650°C (3,002 °F).
Mechanical16
Grade C-3-SR has a yield strength of 505 MPa (73.2 ksi) and a tensile strength of 605 MPa (87.7 ksi) — weaker than 62% of titanium grades. Elongation at break is 16% and the elastic modulus is 104 GPa (15.1 Msi).
Thermal6
Grade C-3-SR is rated for continuous service to 400°C (752 °F). It conducts heat at 17.2 W/m·K (9.94 BTU/hr·ft·°F), better than 88% of titanium grades. Thermal expansion is 8.6 µm/m·K (4.78 µin/in·°F).
Electrical3
Grade C-3-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-3-SR takes about 700 MJ of energy and emits 45 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 30%.
Manufacturability8
Grade C-3-SR's machinability is poor (34/100, better than 74% of titanium grades); weldability excellent (85/100); 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-3-SR
Is Grade C-3 easy to machine?
Machine with sharp uncoated-carbide or PVD tools, low surface speed (~30–50 m/min), heavy positive rake, rigid setup and flood coolant; never dwell, and control chip fire risk.
Can Grade C-3 be welded?
Readily GTAW/EBW/plasma welded to itself with matching or lower-oxygen filler under full argon/helium shielding including trailing and back purge; keep weld colour silver, avoid any contamination for weld repair per AWS D17.1.
Can Grade C-3 be formed, bent or molded?
Supplied as investment or rammed-graphite castings poured in vacuum/inert atmosphere; allow generous fillets and feeders, and specify HIP for pressure-tight or fatigue-critical parts — cold forming is not applicable.
What surface finishes work on Grade C-3?
Chemical mill/pickle in HNO₃–HF to remove the alpha case, then bead blast, polish or colour-anodize; avoid iron contamination from steel tooling to preserve corrosion resistance.
Grade C-3 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 |
|---|---|---|
| N | ≤ 0.05 | 0.02 |
| C | ≤ 0.1 | 0.03 |
| H | ≤ 0.02 | 0.01 |
| Fe | ≤ 0.4 | 0.25 |
| Oprincipal strengthener; higher than C-1/C-2 | ≤ 0.4 | 0.32 |
| Residuals (each)each, max | ≤ 0.1 | — |
| Residuals (total)total, max | ≤ 0.4 | — |
| Ti | balance | — |
Grade C-3-SR — frequently asked
What is Grade C-3-SR used for?
Grade C-3-SR is typically used for aerospace brackets, marine fittings, surgical instrument castings and industrial valve trim. In short: strongest unalloyed cast titanium; corrosion score 93; step up from C-2.
What is the yield strength of Grade C-3-SR?
Grade C-3-SR has a typical yield strength of 505 MPa (73.2 ksi) and a tensile strength of 605 MPa (87.7 ksi) — weaker than 62% of titanium grades. Strength varies by condition: see the 4 listed tempers.
Is Grade C-3-SR easy to machine?
Not especially — machinability is rated poor (34/100, better than 74% of titanium grades). Machine with sharp uncoated-carbide or PVD tools, low surface speed (~30–50 m/min), heavy positive rake, rigid setup and flood coolant; never dwell, and control chip fire risk.
Can Grade C-3-SR be welded?
Yes — weldability is rated excellent (85/100). Readily GTAW/EBW/plasma welded to itself with matching or lower-oxygen filler under full argon/helium shielding including trailing and back purge; keep weld colour silver, avoid any contamination for weld repair per AWS D17.1.
What surface finishes work on Grade C-3-SR?
Chemical mill/pickle in HNO₃–HF to remove the alpha case, then bead blast, polish or colour-anodize; avoid iron contamination from steel tooling to preserve corrosion resistance.
Can Grade C-3-SR be formed, bent or molded?
Supplied as investment or rammed-graphite castings poured in vacuum/inert atmosphere; allow generous fillets and feeders, and specify HIP for pressure-tight or fatigue-critical parts — cold forming is not applicable.
What is the maximum service temperature of Grade C-3-SR?
Grade C-3-SR 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-3-F and Grade C-3-SR?
F is the default condition — standard supply condition for non-critical corrosion hardware where residual microporosity is acceptable. SR: use after heavy weld repair or rough machining to remove residual stress and stabilise dimensions. Yield strength is 520 MPa in F versus 505 MPa in SR.
Sources
- ASTM B367 — Standard Specification for Titanium and Titanium Alloy Castings — ASTM International (2022)
- ASTM B265 / ASTM F67 (wrought CP-Ti Grade 4 reference values) — ASTM International (2020)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (Titanium) — ASM International (2005)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
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.