Titanium Grade C-2
ASTM B367 Grade C-2
Grade C-2 (UNS R50550) is an unalloyed, commercially pure titanium casting grade in the ASTM B367 family, strengthened only by controlled oxygen and iron rather than by alloying additions.
Reference datasheet — Grade C-2 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-2 tempers and conditions
Grade C-2 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 |
|---|---|---|---|---|---|---|
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 |
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?
Grade C-2 (UNS R50550) is an unalloyed, commercially pure titanium casting grade in the ASTM B367 family, strengthened only by controlled oxygen and iron rather than by alloying additions. It is chosen for corrosion-resistant net-shape parts — investment or rammed-graphite castings such as valve bodies, pump housings and marine hardware — where 385 MPa yield, 480 MPa tensile and 16 % elongation are sufficient. Service is limited to about 315 °C and strength is modest; where more load capacity is needed in the same environment, Grade C-3 or cast Ti-6Al-4V (C-5) is the usual step up. Grade C-2 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). Grade C-2 has a yield strength of 385 MPa (55.8 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 69% of titanium grades. Elongation at break is 16% and the elastic modulus is 103 GPa (14.9 Msi).
What is Grade C-2 used for?
- marine hardware castings
- chemical process valve bodies
- pump housings
- medical instrument castings
Advantages
- Easy to machine — 35/100, better than 78% of titanium grades
- High electrical conductivity — 3.1 % IACS, better than 75% of titanium grades
Grade C-2 properties
Typical room-temperature values for Grade C-2-F; bars are the position among titanium grades.
Physical3
Grade C-2 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 has a yield strength of 385 MPa (55.8 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 69% of titanium grades. Elongation at break is 16% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
Grade C-2 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 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 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's machinability is fair (35/100, better than 78% of titanium grades); weldability excellent (85/100); 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-2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Grade C-2
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.
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 |
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.
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-2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B367 Grade C-2
- Similar grades
- R50550
How much does Grade C-2 cost?
Grade C-2 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-2 — frequently asked
What is Grade C-2 used for?
Grade C-2 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?
Grade C-2 has a typical yield strength of 385 MPa (55.8 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 69% of titanium grades. Strength varies by condition: see the 4 listed tempers.
Is Grade C-2 easy to machine?
Not especially — machinability is rated fair (35/100, better than 78% 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 be welded?
Yes — weldability is rated excellent (85/100). 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?
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 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?
Grade C-2 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.
How much does Grade C-2 cost?
Grade C-2 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 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; 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.