Titanium Grade C-3
ASTM B367 Grade C-3
Grade C-3 (UNS R50700) is the higher-strength commercially pure titanium casting grade of the ASTM B367 family, using a higher controlled oxygen content than C-2 to reach 520 MPa yield and 620 MPa tensile with 14 % elongation.
Reference datasheet — Grade C-3 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 F condition
Grade C-3 tempers and conditions
Grade C-3 is supplied in 4 conditions, soft to hard. F is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
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?
Grade C-3 (UNS R50700) is the higher-strength commercially pure titanium casting grade of the ASTM B367 family, using a higher controlled oxygen content than C-2 to reach 520 MPa yield and 620 MPa tensile with 14 % elongation. Engineers specify it as investment or rammed-graphite castings for valve trim, fittings and brackets that need cast-in geometry plus a corrosion resistance score of 93. The extra interstitial oxygen costs ductility and raises the alpha-case problem, and service is capped near 400 °C; drop to C-2 where formability and toughness matter more, or move to C-5 for structural loads. Grade C-3 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). Grade C-3 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of titanium grades. Elongation at break is 14% and the elastic modulus is 104 GPa (15.1 Msi).
What is Grade C-3 used for?
- aerospace brackets
- marine fittings
- surgical instrument castings
- industrial valve trim
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
Limitations
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 83% of titanium grades
Grade C-3 properties
Typical room-temperature values for Grade C-3-F; bars are the position among titanium grades.
Physical3
Grade C-3 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 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of titanium grades. Elongation at break is 14% and the elastic modulus is 104 GPa (15.1 Msi).
Thermal6
Grade C-3 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 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 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's machinability is poor (32/100, better than 70% of titanium grades); weldability very good (82/100); 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-3 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Grade C-3
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.
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 |
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.
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-3 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B367 Grade C-3
- Similar grades
- R50700
How much does Grade C-3 cost?
Grade C-3 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-3 — frequently asked
What is Grade C-3 used for?
Grade C-3 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?
Grade C-3 has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of titanium grades. Strength varies by condition: see the 4 listed tempers.
Is Grade C-3 easy to machine?
Not especially — machinability is rated poor (32/100, better than 70% 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 be welded?
Yes — weldability is rated very good (82/100). 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?
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 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?
Grade C-3 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.
How much does Grade C-3 cost?
Grade C-3 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 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; 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.