FabDigitFabDigit

Refractory Metal C-103 vs C-129Y

Refractory Metal · grade comparison

Refractory Metal C-103 and C-129Y are both refractory metal grades. C-129Y is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 275 MPa (39.9 ksi) for C-103, about 75% more; tensile strength follows at 585 MPa (84.8 ksi) vs 415 MPa (60.2 ksi). In exchange, C-103 is the more ductile: elongation 25% versus 22% for C-129Y, and C-129Y is harder (220 HV vs 180 HV). C-103 is lighter (8.85 g/cm³ vs 9.46 g/cm³ for C-129Y) and C-129Y is stiffer (131 GPa vs 88 GPa). On the shop floor, C-103 welds better (80 vs 70 out of 100) and C-129Y sits in a lower cost tier (high, $$$$) than C-103 (specialty, $$$$$).

C-103Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

C-129YChoose it when strength drives the design, or when cost is the deciding factor.

C-103 vs C-129Y: properties

C-103C-129Y

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

88 GPa12.8 Msi
131 GPa19 Msi

Shear Modulus

33 GPa4.8 Msi
48 GPa7 Msi

Bulk Modulus

98 GPa14.2 Msi
165 GPa23.9 Msi

Poisson's Ratio

0.35
0.36

Tensile Strength (Ultimate)

415 MPa60.2 ksi
585 MPa84.8 ksi

Yield Strength (0.2% offset)

275 MPa39.9 ksi
480 MPa69.6 ksi

Elongation at Break

25%
22%

Reduction in Area

55%
45%

Shear Strength

250 MPa36.3 ksi
360 MPa52.2 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
280 MPa40.6 ksi

Hardness, Rockwell B

85 HRB
95 HRB

Hardness, Vickers

180 HV
220 HV

Compressive Strength

—
490 MPa71.1 ksi

Fracture Toughness (K_IC)

—
90 MPa·√m81.9 ksi·√in

Charpy V-Notch Impact (RT)

—
40 J29.5 ft·lbf

Hardness, Brinell

—
209 HB

Hardness, Rockwell C

—
18 HRC

Physical

Density and transition temperatures.

Density

8.85 g/cm³0.32 lb/in³
9.46 g/cm³0.34 lb/in³

Melting Point (Solidus)

2,350°C4,262 °F
2,450°C4,442 °F

Liquidus Temperature

2,400°C4,352 °F
2,520°C4,568 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
32 W/m·K18.5 BTU/hr·ft·°F

Specific Heat Capacity

272 J/kg·K0.06 BTU/lb·°F
270 J/kg·K0.06 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

7.4 µm/m·K4.1 µin/in·°F
7.5 µm/m·K4.2 µin/in·°F

Same in both: Latent Heat of Fusion 285 J/g123 BTU/lb · Max Service Temperature (continuous) 1,400°C2,552 °F · Min Service Temperature -253°C-423 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

5.1 % IACS
3.6 % IACS

Electrical Resistivity

3.4×10⁻⁷ Ω·m13.4 µΩ·in
4.8×10⁻⁷ Ω·m18.9 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

62 / 100
68 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.15 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

30 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

25%
20%

Weldability

80 / 100
70 / 100

Formability (cold)

85 / 100
65 / 100

Castability

20 / 100
—

Brazeability / Solderability

60 / 100
55 / 100

Same in both: Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

900 MJ/kg386,931 BTU/lb
620 MJ/kg266,552 BTU/lb

Embodied Carbon (primary production)

55 kg CO₂/kg
42 kg CO₂/kg

Embodied Water

—
900 L/kg108 gal/lb

Same in both: Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

47 kN·m/kg
62 kN·m/kg

Specific Stiffness (E / density)

9.9 MN·m/kg
13.8 MN·m/kg

Modulus of Resilience

430 kJ/m³
879 kJ/m³

Thermal Diffusivity

17.4 mm²/s
12.5 mm²/s

Thermal Shock Resistance Index

27
19

Strength versus weight

Yield strength against density for every refractory metal grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

1502003005007001,0001,5005101520Density (g/cm³)Yield strength (MPa) — log scaleC-103C-129Y

Manufacturing and finishing

CapabilityC-103C-129Y
Default conditionVacuum Annealed—
Relative cost$$$$$ Specialty$$$$ High
Min. machined wall——
Best machined surface——

C-103 vs C-129Y — frequently asked

Is C-129Y stronger than C-103?

Yes. C-129Y has a typical yield strength of 480 MPa (69.6 ksi) against 275 MPa (39.9 ksi) for C-103 — about 75% more. Tensile strength is 585 MPa (84.8 ksi) vs 415 MPa (60.2 ksi).

Which is cheaper, C-103 or C-129Y?

C-129Y is the lower-cost material: it sits in the high tier ($$$$) while C-103 is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, C-103 or C-129Y?

C-103, by a small margin. Both rate poor for machinability — 30/100 against 25/100 for C-129Y; for welding the order is C-103 first (very good, 80/100) then C-129Y (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C-103 and C-129Y side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.