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Refractory Metal C-103 · supply condition

Refractory Metal C-103 Cold Worked

Properties of the Cold Worked condition, compared with the other C-103 tempers.

Highest room-temperature strength; use for springs, fasteners and thin foil where no hot service or forming follows.

CNC machiningSheet metalSpecialty cost $$$$$

What is C-103 Cold Worked?

C-103 Cold Worked is C-103 supplied in the Cold Worked condition — highest room-temperature strength; use for springs, fasteners and thin foil where no hot service or forming follows. C-103 Cold Worked has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 85% of refractory metal grades. Elongation at break is 8% and the elastic modulus is 88 GPa (12.8 Msi). C-103 Cold Worked has a density of 8.85 g/cm³ (0.32 lb/in³), heavier than 56% of refractory metal grades. It melts at 2,350°C (4,262 °F). Vacuum Annealed is the default condition FabDigit quotes; Cold Worked is available on request or by drawing note.

Advantages

  • Easy to machine — 40/100, better than 93% of refractory metal grades
  • High strength — 620 MPa (89.9 ksi), better than 85% of refractory metal grades

Limitations

  • Low stiffness — 88 GPa (12.8 Msi), worse than 99% of refractory metal grades
  • Limited ductility — 8%, worse than 78% of refractory metal grades

C-103 Cold Worked properties

Typical room-temperature values for C-103 Cold Worked — 9 properties are specific to this condition; the rest are grade-level values shared by every C-103 temper. Each bar shows where the value sits among the refractory metal grades in FabDigit's library — further right is higher.

Physical3

C-103 Cold Worked has a density of 8.85 g/cm³ (0.32 lb/in³), heavier than 56% of refractory metal grades. It melts at 2,350°C (4,262 °F).

Density8.85 g/cm³0.32 lb/in³
Melting Point (Solidus)2,350°C4,262 °F
Liquidus Temperature2,400°C4,352 °F

Mechanical12

C-103 Cold Worked has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 85% of refractory metal grades. Elongation at break is 8% and the elastic modulus is 88 GPa (12.8 Msi).

Elastic (Young's) Modulus88 GPa12.8 Msi
Shear Modulus33 GPa4.8 Msi
Bulk Modulus98 GPa14.2 Msi
Poisson's Ratio0.35
Tensile Strength (Ultimate)690 MPa100 ksi
Yield Strength (0.2% offset)620 MPa89.9 ksi
Elongation at Break8%
Reduction in Area55%
Shear Strength250 MPa36.3 ksi
Fatigue Strength (Endurance Limit)200 MPa29 ksi
Hardness, Rockwell B100 HRB
Hardness, Vickers260 HV

Thermal6

C-103 Cold Worked is rated for continuous service to 800°C (1,472 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), better than 50% of refractory metal grades. Thermal expansion is 7.4 µm/m·K (4.11 µin/in·°F).

Thermal Conductivity42 W/m·K24.3 BTU/hr·ft·°F
Specific Heat Capacity272 J/kg·K0.06 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)7.4 µm/m·K4.1 µin/in·°F
Latent Heat of Fusion285 J/g123 BTU/lb
Max Service Temperature (continuous)800°C1,472 °F
Min Service Temperature-253°C-423 °F

Electrical3

C-103 Cold Worked conducts electricity at 5.1 % IACS, worse than 59% of refractory metal grades.

Electrical Conductivity5.1 % IACS
Electrical Resistivity3.4×10⁻⁷ Ω·m13.4 µΩ·in
Magnetic Responsenon-magnetic (paramagnetic)

Chemical & Environmental3

Corrosion resistance is good (62/100), worse than 66% of refractory metal grades.

Galvanic Potential (seawater, vs SCE)-0.15 V
Corrosion ResistanceGood62/100
Chemical Resistance SummaryPassive and highly resistant in most mineral acids, chlorides and liquid alkali metals (Na, K, Li); attacked by HF, fluorides, hot concentrated alkalis; absorbs H, O and N above ~250–400 °C, so bare service in air is limited to ~400 °C.

Sustainability3

Producing a kilogram of C-103 Cold Worked takes about 900 MJ of energy and emits 55 kg of CO₂ — less than 59% of refractory metal grades. Typical recycled content is 25%.

Embodied Energy (primary production)900 MJ/kg386,931 BTU/lb
Embodied Carbon (primary production)55 kg CO₂/kg
Typical Recycled Content25%

Manufacturability8

C-103 Cold Worked's machinability is fair (40/100, better than 93% of refractory metal grades); weldability good (65/100); formability fair (35/100).

MachinabilityFair40/100
Machinability Rating (AISI 1212 = 100 %)25%
WeldabilityGood65/100
Formability (cold)Fair35/100
CastabilityPoor20/100
Brazeability / SolderabilityGood60/100
PolishabilityGood60/100
Anodizing Responsen/a for decorative use; Nb anodizes to interference colours in dilute electrolytes, but service protection is by R512E silicide or Si–Cr–Fe slurry coating

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Other C-103 tempers and conditions

C-103 is also supplied in 3 other conditions. The full side-by-side table is on the C-103 overview.

Working with C-103 Cold Worked

Is C-103 easy to machine?

Gummy and galling like tantalum — use sharp, high-positive-rake carbide or HSS tools, slow speed, heavy feed, generous chlorinated or water-soluble coolant, and avoid dwelling; grind with SiC and plenty of coolant.

Can C-103 be welded?

Excellent GTAW/EBW/laser weldability, but only in vacuum or high-purity inert chambers/trailing shields — any O, N or H pickup embrittles the weld; clean and pickle before welding, no filler usually needed.

Can C-103 be formed, bent or molded?

Very ductile cold: deep draws, spins and rolls readily with clean tooling and non-chlorinated lubricant; interstage vacuum anneals restore ductility, and hot working is done above ~1100 °C under protection.

What surface finishes work on C-103?

Chemically pickle (HNO₃/HF) then apply R512E silicide or Si-Cr slurry coating for oxidation service; electropolishing and anodic colouring are possible but coating adhesion prep governs flight hardware.

C-103 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.

ElementSpec limit (wt %)Nominal
Hf9 – 1110
Ti0.7 – 1.31
Zrresidual from Hf source≤ 0.70.5
Ta≤ 0.5
W≤ 0.5
C≤ 0.02
O≤ 0.03
N≤ 0.01
H≤ 0
Fe≤ 0.01
Ni≤ 0.01
Si≤ 0.01
Nbbalance

C-103 Cold Worked — frequently asked

What is C-103 Cold Worked used for?

C-103 Cold Worked is typically used for rocket nozzle extensions and inserts, spacecraft thruster combustion chambers, rocket engine thrust chamber liners, hot gas structures and leading edges, radiation shields and heat shields and high-temperature furnace fixtures. In short: aerospace high-temp niobium.

What is the yield strength of C-103 Cold Worked?

C-103 Cold Worked has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 85% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.

Is C-103 Cold Worked easy to machine?

Not especially — machinability is rated fair (40/100, better than 93% of refractory metal grades). Gummy and galling like tantalum — use sharp, high-positive-rake carbide or HSS tools, slow speed, heavy feed, generous chlorinated or water-soluble coolant, and avoid dwelling; grind with SiC and plenty of coolant.

Can C-103 Cold Worked be welded?

Yes — weldability is rated good (65/100). Excellent GTAW/EBW/laser weldability, but only in vacuum or high-purity inert chambers/trailing shields — any O, N or H pickup embrittles the weld; clean and pickle before welding, no filler usually needed.

What surface finishes work on C-103 Cold Worked?

Chemically pickle (HNO₃/HF) then apply R512E silicide or Si-Cr slurry coating for oxidation service; electropolishing and anodic colouring are possible but coating adhesion prep governs flight hardware.

Can C-103 Cold Worked be formed, bent or molded?

Very ductile cold: deep draws, spins and rolls readily with clean tooling and non-chlorinated lubricant; interstage vacuum anneals restore ductility, and hot working is done above ~1100 °C under protection.

What is the maximum service temperature of C-103 Cold Worked?

C-103 Cold Worked is rated for continuous use to about 800°C (1,472 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Can FabDigit make parts in C-103 Cold Worked?

Yes — C-103 Cold Worked is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.

Sources

  1. ASTM B654 — Niobium-Hafnium Alloy Foil, Sheet, Strip and PlateASTM International (2020)
  2. ASTM B652 — Niobium-Hafnium Alloy IngotsASTM International (2020)
  3. ASTM B655 — Niobium-Hafnium Alloy Bar, Rod and WireASTM International (2020)
  4. ASM Handbook Vol. 2 — Properties of Refractory Metals and AlloysASM International (1990)
  5. C-103 (Nb-10Hf-1Ti) alloy datasheetATI / Wah Chang refractory metals (2019)
  6. Refractory-metal nozzle materials and R512E coating performance summariesNASA technical reports (1972)

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.