ASTM B655 C-103 Niobium-Hafnium Alloy Bar and Rod
- Type: Bar and Rod
- Niobium-Hafnium Alloy
- Standard: ASTM B655/B655M
- Grade: UNS R04295, 89Nb-10Hf-1Ti, C-103, Nb10Hf1Ti
- Condition: Annealed / Cold Worked / Stress-Relieved
- Surface Finish: Clean, Bright Finish
- Form: Bar / Rod / Wire
- Inspection: EN 10204 3.1 / 3.2
- Size Range: Square/Rectangular bar 5–50 mm × 50–150 mm; Round/Hex/Oct rod Ø3.2–64 mm
- Application: Aerospace / Rocket Propulsion / High-Temperature Service
ASTM B655 C-103 Niobium-Hafnium Alloy Bar and Rod
ASTM B655 C-103 Niobium-Hafnium Alloy Bar and Rod (UNS R04295 / Nb-10Hf-1Ti) is a premium high-temperature refractory alloy engineered for the most extreme aerospace and propulsion environments. By alloying niobium with approximately 10% hafnium and 1% titanium, C-103 delivers exceptional tensile strength, creep resistance, and oxidation performance at temperatures up to 2000 °F (1100 °C) and beyond, while maintaining excellent room-temperature ductility and superior weldability—properties that significantly outperform pure niobium. Manufactured strictly to ASTM B655/B655M standards and supplied in annealed, cold-worked, or stress-relieved conditions with a clean, bright surface finish, this alloy is the material of choice for rocket engine nozzles, thrusters, spacecraft components, jet engine hot-section parts, and other critical high-temperature structural applications in aerospace, defense, and advanced industrial systems. Available in round, square, rectangular, hexagonal, and octagonal bar and rod forms (as well as wire), Golden Sunbird Metals’ C-103 products offer reliable performance, full traceability, and EN 10204 3.1/3.2 certification to meet the stringent requirements of critical missions and extreme environments.
UNS R04295, 89Nb-10Hf-1Ti, C-103, Nb10Hf1Ti Niobium-Hafnium alloy Bar and Rod Chemical Composition (wt.%)
| Chemical Requirements for Ingot Niobium-Hafnium Alloy R04295 Element Content, Maximum Weight %
(Except Where Otherwise Specified) |
||||||||||
| UNS No. | C, max | O, max | N, max | H, max | Hf, max | Ti, max | Zr, max | W, max | Ta, max | Nb, max |
| UNS R04295 | 0.015 | 0.025 | 0.010 | 0.0015 | 9-11 | 0.7-1.3 | 0.7 | 0.5 | 0.5 | Balance |
| Additional Chemical Requirements for Finished Product of Niobium-Hafnium Alloy R04295 Element Content, Maximum Weight % |
||||
| UNS No. | C, max | O, max | N, max | H, max |
| UNS R04295 | 0.035 | 0.015 | 0.010 | 0.0015 |
UNS R04295, 89Nb-10Hf-1Ti, C-103, Nb10Hf1Ti Niobium-Hafnium alloy Bar and Rod Mechanical Properties
| Mechanical Properties for Material, Annealed Condition (90 % Minimum Recrystallized) |
|||
| Conditions | Tensile Strength （Mpa) |
Yield Strength (Mpa) |
Elongation % |
| Material 0.05 in. [1.3 mm] and thinner: Room temperature 2000 6 25°F [1100 6 15°C] |
385 | 275 | 20 |
| 145 | 110 | 20 | |
| Material greater than 0.05 in. [1.3 mm] in thickness: Room temperature 2000 6 25°F [1100 6 15°C] |
370 | 260 | 20 |
| 145 | 110 | 20 | |
Features
- ASTM B655/B655M niobium-hafnium alloy bar, rod, and wire for high-temperature aerospace and space applications.
- Available as UNS R04295, 89Nb-10Hf-1Ti, C-103, Nb10Hf1Ti, a Niobium-base alloy containing approximately 10% Hafnium and 1% Titanium.
- High strength at elevated temperature with excellent load-bearing performance for demanding propulsion environments.
- Good thermal conductivity, weldability, and room-temperature ductility compared with many refractory metals.
- Supplied in annealed, cold-worked, and stress-relieved conditions with clean, bright surface finish.
- Available in bar, rod, and wire dimensions to support machining, forming, and fabrication.
Technical Specifications
| Specification | Value |
| Standard | UNS R04295, 89Nb-10Hf-1Ti, C-103, Nb10Hf1Ti Niobium-Hafnium alloy Bar and Rod |
| Grade | UNS R04295, 89Nb-10Hf-1Ti, C-103, Nb10Hf1Ti |
| Condition & Finish | Annealed, cold worked, and stress-relieved; clean, bright finish, free of defects and surface imperfections. |
| Type | Bar, Rod, Wire |
| Dimension | Square / Rectangular bar size: Thickness: 5 – 50mm x Width: 50 – 150mm |
| Round / Hexagonal / Octagonal rod size: Dia. 3.2 – 64mm | |
| Coiled, Spooled or Reeled wire size: Dia. 0.5 – 3.2mm | |
| Inspection Certificate | EN 10204 Type 3.1 (Mill Test Certificate), EN 10204 Type 3.2 (Witness Testing or 3rd Party Inspection) |
| Test | Chemical analysis, Tensile test, Hardness test, Microstructural examination |
Packing & Shipment
To ensure product safety during storage, handling, and international transportation, niobium-hafnium alloy (C-103 / UNS R04295) bars and rods are packed with corrosion protection and impact protection measures according to product size, quantity, and shipping mode.
| Item | Packing / Shipment Method |
| Internal Protection | Bars and rods are thoroughly cleaned, dried, and free of all contaminants before packing; all surfaces receive a temporary protective film or oil-free coating suitable for refractory metals. |
| Sealing Protection | Each bundle or individual piece is placed in sealed PE bags or vacuum-sealed packaging to prevent dust, moisture, and oxidation. |
| Surface Protection | Critical bright-finish surfaces are covered with soft non-woven fabric, EPE foam liners, or protective paper to prevent scratches and maintain the clean surface condition. |
| Individual Packing | Smaller diameter rods and bars are individually wrapped with PE film and packed in sturdy plywood boxes or export-grade wooden crates with sufficient cushioning materials. |
| Large / Long Bar & Rod Packing | Longer bars or heavy rods are bundled, clearly labeled, and secured on wooden pallets or reinforced export crates; each bundle includes assembly/handling instructions where applicable. |
| Shock Protection | High-density foam padding, internal bracing, wooden blocking, and heavy-duty strapping are used to prevent movement and impact during transit. |
| Moisture Control | Desiccant bags and humidity indicator cards are placed inside the sealed package to control moisture and prevent oxidation. |
| Marking | Package labels include product name, grade (C-103 / UNS R04295), dimensions, condition (annealed / cold worked / stress-relieved), quantity, net/gross weight, heat number, and shipping marks. |
| Shipping Mode | By sea (FCL / LCL), air freight, or multimodal transport depending on order quantity and delivery requirements. |
| Documents | Packing list, commercial invoice, certificate of origin, material test certificates (EN 10204 3.1 / 3.2), chemical analysis reports, and inspection documents provided. |
Applications
- High-thrust rocket nozzles and other rocket propulsion components.
- Spacecraft and launch vehicle parts requiring high strength at elevated temperature.
- Satellite components exposed to cryogenic vibration and thermal cycling.
- Jet engine afterburner flap sections and related hot-zone aerospace parts.
- High-temperature defense and space-system structural components.
