Titanium C-12
ASTM B367 Grade C-12
C-12 is the cast version of the Ti-0.3Mo-0.8Ni alloy, supplied to ASTM B367 as Grade C-12, and provides crevice-corrosion resistance approaching Grade 7 palladium-bearing alloys at lower cost.
Reference datasheet — C-12 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 A condition
C-12 tempers and conditions
C-12 is supplied in 5 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
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 corrosion hardware where internal porosity is acceptable. | 450 | 550 | 10 | 215 HB | 3.3 % IACS |
Stress relieved | Pick when casting is heavily weld-repaired or machined and residual stress/distortion must be controlled without full anneal. | 450 | 555 | 11 | 210 HB | 3.3 % IACS |
ADefault Solution annealed | Standard supply condition for ASTM B367 C-12 castings: stable microstructure, best ductility-to-strength balance for chemical plant service. | 455 | 560 | 12 | 210 HB | 3.3 % IACS |
Hot isostatically pressed and annealed | Highest-integrity condition: HIP densification followed by anneal to relieve HIP-cycle stresses and stabilise properties. | 455 | 565 | 17 | 205 HB | 3.3 % IACS |
Hot isostatic pressed | Choose for pressure-boundary or fatigue-loaded castings: closes internal porosity and lifts ductility and fatigue life. | 460 | 570 | 16 | 210 HB | 3.3 % IACS |
What is C-12?
C-12 is the cast version of the Ti-0.3Mo-0.8Ni alloy, supplied to ASTM B367 as Grade C-12, and provides crevice-corrosion resistance approaching Grade 7 palladium-bearing alloys at lower cost. It is chosen for vacuum-melted castings in seawater, brine and chemical process service, available as-cast, stress-relieved, annealed, HIP or HIP + annealed. Strength is modest (455 MPa yield, 560 MPa tensile, 12 % elongation, 210 HB) and maximum service temperature is about 315 °C, so cast Ti-6Al-4V grades are the alternative when load capacity governs rather than corrosion. C-12 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). C-12 has a yield strength of 455 MPa (66 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 63% of titanium grades. Elongation at break is 12% and the elastic modulus is 103 GPa (14.9 Msi).
What is C-12 used for?
- seawater piping components
- heat-exchanger castings
- chemical process housings
Advantages
- Conducts heat well — 19 W/m·K (11 BTU/hr·ft·°F), better than 93% of titanium grades
- High electrical conductivity — 3.3 % IACS, better than 92% of titanium grades
Limitations
- Limited ductility — 12%, worse than 78% of titanium grades
C-12 properties
Typical room-temperature values for C-12-A; bars are the position among titanium grades.
Physical3
C-12 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
C-12 has a yield strength of 455 MPa (66 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 63% of titanium grades. Elongation at break is 12% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C-12 is rated for continuous service to 315°C (599 °F). It conducts heat at 19 W/m·K (11 BTU/hr·ft·°F), better than 93% of titanium grades. Thermal expansion is 9.5 µm/m·K (5.28 µin/in·°F).
Electrical3
C-12 conducts electricity at 3.3 % IACS, better than 92% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (93/100), better than 72% of titanium grades.
Sustainability4
Producing a kilogram of C-12 takes about 700 MJ of energy and emits 42 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 25%.
Manufacturability8
C-12's machinability is poor (28/100, better than 59% of titanium grades); weldability excellent (85/100); formability poor (30/100).
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. C-12 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C-12
Is C-12 easy to machine?
Machine like CP Ti but slightly harder: low surface speed (25–45 m/min carbide), heavy positive rake, rigid setup, flood coolant and never dwell — chips are pyrophoric and work-hardening/galling is the main failure mode.
Can C-12 be welded?
Excellent GTAW/EBW weldability with matching Gr12 filler; requires full argon/helium shielding of pool, root and trailing HAZ, cleanliness to avoid O/N/H pickup, and interpass temperature below ~200 °C; weld repair of castings is routine and re-HIP is common after major repair.
Can C-12 be formed, bent or molded?
Supplied as vacuum-melted (VAR/skull) castings poured into rammed-graphite or investment moulds under vacuum/argon; allow generous machining stock for the alpha-case layer and specify HIP for pressure-containing parts.
C-12 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 |
|---|---|---|
| Mo | 0.2 – 0.4 | 0.3 |
| Ni | 0.6 – 0.9 | 0.8 |
| Fe | ≤ 0.3 | 0.15 |
| O | ≤ 0.25 | 0.18 |
| C | ≤ 0.08 | 0.03 |
| N | ≤ 0.03 | 0.02 |
| Hmax (castings) | ≤ 0.02 | 0.01 |
| Residuals, eachmax each | ≤ 0.1 | |
| Residuals, totalmax total | ≤ 0.4 | |
| Ti | balance |
What surface finishes work on C-12?
Remove alpha case by chemical milling (HNO3/HF) or grit blast + pickle before service; anodizing (colour or Type III) and passivation are effective, and surfaces polish well although casting porosity can show.
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 C-12 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B367 Grade C-12
How much does C-12 cost?
C-12 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.
C-12 — frequently asked
What is C-12 used for?
C-12 is typically used for seawater piping components, heat-exchanger castings and chemical process housings. In short: low-cost crevice-corrosion cast titanium; excellent weldability; alternative to Grade 7.
What is the yield strength of C-12?
C-12 has a typical yield strength of 455 MPa (66 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 63% of titanium grades. Strength varies by condition: see the 5 listed tempers.
Is C-12 easy to machine?
Not especially — machinability is rated poor (28/100, better than 59% of titanium grades). Machine like CP Ti but slightly harder: low surface speed (25–45 m/min carbide), heavy positive rake, rigid setup, flood coolant and never dwell — chips are pyrophoric and work-hardening/galling is the main failure mode.
Can C-12 be welded?
Yes — weldability is rated excellent (85/100). Excellent GTAW/EBW weldability with matching Gr12 filler; requires full argon/helium shielding of pool, root and trailing HAZ, cleanliness to avoid O/N/H pickup, and interpass temperature below ~200 °C; weld repair of castings is routine and re-HIP is common after major repair.
What surface finishes work on C-12?
Remove alpha case by chemical milling (HNO3/HF) or grit blast + pickle before service; anodizing (colour or Type III) and passivation are effective, and surfaces polish well although casting porosity can show.
Can C-12 be formed, bent or molded?
Supplied as vacuum-melted (VAR/skull) castings poured into rammed-graphite or investment moulds under vacuum/argon; allow generous machining stock for the alpha-case layer and specify HIP for pressure-containing parts.
What is the maximum service temperature of C-12?
C-12 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 C-12-A and C-12-F?
A is the default condition — standard supply condition for ASTM B367 C-12 castings: stable microstructure, best ductility-to-strength balance for chemical plant service. F: lowest-cost condition for non-critical, low-stress corrosion hardware where internal porosity is acceptable. Yield strength is 455 MPa in A versus 450 MPa in F.
How much does C-12 cost?
C-12 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 / B348 Titanium Grade 12 (wrought reference) — ASTM International (2020)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- TIMETAL Code 12 (Ti-0.3Mo-0.8Ni) corrosion and property data — TIMET (2018)
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.