Niobium Fittings Supplier – Pure Niobium, Nb-1Zr, C-103 & Nb-Ti Fittings
ASC LLP, Mumbai, is a niobium alloy fittings supplier offering elbows, tees, reducers, caps, stub ends, couplings and machined fittings in every commercial niobium grade – pure niobium R04200 and R04210, Nb-1Zr (R04251, R04261), C-103 and Nb-47Ti – made from ASTM-certified bar, tube and sheet, with EN 10204 3.1 certificates. Browse the full niobium & niobium alloy range.
What are Niobium Fittings?
Niobium fittings are pipe fittings made from niobium or niobium alloys for corrosive, high-purity, high-temperature (vacuum or inert gas) and cryogenic systems. There is no separate ASTM standard for niobium fittings – they are formed from ASTM B394 tube, machined from ASTM B392 bar or formed from ASTM B393 sheet and plate, and carry the grade and test requirements of that material.
Niobium Fittings by Grade
Choose a grade to see chemistry, mechanical properties, fitting types and specifications.
| Grade | Fittings pages |
| Pure niobium – R04200 (reactor grade) | R04200 fittings (from bar, B392) · R04200 fittings (from tube, B394) |
| Pure niobium – R04210 (commercial grade) | R04210 fittings (B393) · R04210 fittings (from tube, B394) |
| Nb-1Zr – R04251 / R04261 | Nb-1Zr fittings (both grades) · R04251 fittings (from bar) · R04251 fittings (from tube) · R04251 niobium fittings |
| C-103 (Nb-10Hf-1Ti) | C-103 niobium fittings |
| Nb-47Ti (NbTi) | Nb-47Ti fittings & components · Nb-Ti fittings |
| Sheet-formed fittings | Niobium sheet fittings |
| Matching products | Niobium flanges · Niobium fasteners · Niobium seamless pipes · Niobium welded pipes · All niobium products |

Niobium Fitting Grades Compared
| Grade | UNS | Main alloying | Tensile / yield (min, annealed) | Best for |
| Pure niobium, reactor grade | R04200 | None | 125 / 73 MPa | Acid service, high-purity, superconducting and vacuum systems |
| Pure niobium, commercial grade | R04210 | None | 125 / 73 MPa | General acid service at lower cost |
| Nb-1Zr, reactor / commercial | R04251 / R04261 | 0.8–1.2% Zr | 195 / 125 MPa | Liquid-metal, nuclear and high-temperature vacuum service |
| C-103 | R04295 | 10% Hf, 1% Ti | 370 / 260 MPa | Load-bearing parts at very high temperature (aerospace) |
| Nb-47Ti | – | 46–48% Ti | Hardness < 170 HV (B884) | Superconducting and cryogenic components |
Minimum values for annealed material: pure niobium and Nb-1Zr per ASTM B392 / B394; C-103 per ASTM B655; Nb-47Ti per ASTM B884.
Types of Niobium Fittings
| Fitting type | How it is made | Dimensional profile |
| Butt-weld elbows (45°, 90°, 180°) | Formed from ASTM B394 seamless or welded tube | ASME B16.9 or drawing |
| Equal & reducing tees | Formed from tube or machined from bar | ASME B16.9 or drawing |
| Concentric & eccentric reducers | Formed from tube | ASME B16.9 or drawing |
| Caps & stub ends | Formed from ASTM B393 plate or machined from B392 bar | ASME B16.9 or drawing |
| Socket-weld & threaded fittings | Machined from ASTM B392 bar | ASME B16.11 or drawing |
| Couplings, unions, bushings, plugs | Machined from bar | ASME B16.11 or drawing |
ASME B16 standards are used for dimensions only – they give no pressure rating for niobium. Pressure ratings come from the purchaser’s design calculation.


Sizes, Testing & Certification
| Item | Details |
| Sizes | Small-bore typical – about ½” to 4″ NB, or tube OD × wall to order; larger to drawing |
| Wall | SCH 5S, 10S, 40S, 80S or specified wall |
| Ends | Butt-weld (square or bevelled), socket-weld, threaded |
| Condition | Annealed (at least 90% recrystallized), pickled and clean |
| Testing | Chemical incl. interstitials (C, O, N, H), tensile on raw material, dimensional, visual, dye penetrant |
| Certificate | EN 10204 3.1; third-party inspection on request |
Where Niobium Fittings Work – and Where They Don’t
- Good: nitric acid, hydrochloric acid at moderate concentration and temperature, dilute sulphuric and phosphoric acids, most organic acids, chlorides, wet chlorine and bromine, and liquid alkali metals.
- Not suitable: hydrofluoric acid and fluorides, hot concentrated sulphuric acid, oleum and strong alkalis.
- High temperature: niobium and its alloys oxidise in air above about 400 °C – use them hot only in vacuum, inert gas or liquid metal (or C-103 with a silicide coating).
- Hydrogen: avoid galvanic contact with less noble metals in acid, which can make niobium absorb hydrogen and become brittle.
For the hottest, most concentrated acids, tantalum fittings perform better; for moderate conditions, niobium gives similar protection at lower cost and about half the weight.
Niobium Fittings Specifications
| Specification | Covers | Used for |
| ASTM B392 | Niobium & alloy bar, rod, wire | Machined fittings |
| ASTM B393 | Niobium & alloy strip, sheet, plate | Caps, stub ends, fabricated fittings |
| ASTM B394 | Niobium & alloy seamless and welded tube | Butt-weld elbows, tees, reducers |
| ASTM B655 / B654 | C-103 bar / plate | C-103 fittings |
| ASTM B884 | Nb-Ti billet, bar, rod | Nb-47Ti components |
| ASME B16.9 / B16.11 | Fitting dimensions | Profiles only (no niobium ratings) |
Chemical Composition of Niobium Fitting Grades
| Element (max %) | R04200 | R04210 | R04251 | R04261 |
| Zirconium (Zr) | 0.02 | 0.02 | 0.8 – 1.2 | 0.8 – 1.2 |
| Oxygen (O) | 0.015 | 0.025 | 0.015 | 0.025 |
| Carbon (C) | 0.01 | 0.01 | 0.01 | 0.01 |
| Nitrogen (N) | 0.01 | 0.01 | 0.01 | 0.01 |
| Hydrogen (H) | 0.0015 | 0.0015 | 0.0015 | 0.0015 |
| Tantalum (Ta) | 0.1 | 0.3 | 0.1 | 0.5 |
| Tungsten (W) | 0.03 | 0.05 | 0.03 | 0.05 |
| Niobium (Nb) | Remainder | Remainder | Remainder | Remainder |
Main limits per ASTM B392 / B394; full element lists are on each grade page. For C-103 and Nb-47Ti chemistry, see their pages.
Physical Properties of Niobium
| Property | Pure niobium (approx.) |
| Density | 8.57 g/cm³ |
| Melting point | ≈ 2,477 °C (4,491 °F) |
| Thermal conductivity | ≈ 54 W/m·K |
| Coefficient of thermal expansion | ≈ 7.3 µm/m·°C |
| Superconducting transition | ≈ 9.2 K |
Applications of Niobium Fittings
| Industry | Typical niobium fittings use |
| Chemical processing | Acid piping, heat-exchanger and condenser connections, thermowells (pure niobium) |
| Nuclear & space power | Liquid-metal loops and reactor test hardware (Nb-1Zr) |
| Aerospace | Thruster and hot-section hardware (C-103) |
| Superconducting & research | RF-cavity and cryogenic piping (pure niobium, Nb-47Ti) |
| Vacuum & furnace | Vacuum and inert-gas furnace piping and feedthroughs |
How to Order Niobium Fittings
- Grade: R04200, R04210, R04251, R04261, C-103 or Nb-47Ti.
- Fitting type and size: e.g. 90° LR elbow, 1″ SCH 10S – or tube OD × wall.
- Material route: from tube (B394), bar (B392) or plate (B393), if your specification requires one.
- Ends and finish: butt-weld, socket-weld or threaded; pickled or polished.
- Documents: 3.1 certificate, interstitial analysis, third-party inspection if needed.
Matching products: niobium flanges, niobium fasteners, niobium seamless pipes and welded pipes.
Why Buy Niobium Fittings from ASC LLP?
- Every grade: pure niobium, Nb-1Zr, C-103 and Nb-47Ti from one supplier.
- Correct paperwork: certificates state grade, source material standard, chemistry and interstitials.
- Small quantities and drawings welcome: prototypes, test loops and spares.
- Clean, protected export packing and worldwide shipment.
Send grade, fitting type, size and quantity to sales@amardeepsteel.com or call 022-67439130.
Frequently Asked Questions – Niobium Fittings
What are niobium fittings made from?
Niobium fittings are formed from ASTM B394 seamless or welded tube, machined from ASTM B392 bar or formed from ASTM B393 plate, in grades such as R04200, R04210, R04251 and R04261. C-103 fittings use ASTM B655 / B654 material.
Is there an ASTM standard for niobium fittings?
No. There is no separate niobium fittings standard. Fittings take their grade and requirements from the bar, tube or plate standard they are made from, and use ASME B16.9 or B16.11 for dimensions.
Which niobium grade should I choose for fittings?
Use pure niobium R04200 or R04210 for acid service, Nb-1Zr (R04251 / R04261) for liquid-metal and high-temperature vacuum service, C-103 for load-bearing parts at very high temperature, and Nb-47Ti for superconducting and cryogenic components.
What is the strength of niobium fittings?
Annealed pure niobium has a minimum tensile strength of 125 MPa and yield of 73 MPa; Nb-1Zr 195 MPa and 125 MPa; and C-103 370 MPa and 260 MPa.
Can niobium fittings be used at high temperature in air?
No. Niobium and its alloys oxidise in air above about 400 °C. At high temperature they are used in vacuum, inert gas or liquid metal, or – for C-103 – with a protective silicide coating.
Do you supply small quantities of niobium fittings?
Yes. ASC LLP supplies single pieces, prototypes and small batches of niobium fittings in all main grades, with 3.1 certificates and export packing.
Global Reach
ASC LLP supplies niobium, tantalum and other refractory-metal products to chemical, nuclear, aerospace and research customers worldwide, with secure packing and full documentation. Buyers in the USA, Europe, the Middle East and Asia rely on our niobium fittings for certified material and traceability.

Countries We Export To
UNITED STATES, EUROPE, UK, UAE, SAUDI ARABIA, OMAN, KUWAIT, JORDAN, QATAR, INDONESIA, MALAYSIA, BRAZIL, SPAIN, ITALY, FRANCE, GERMANY, BAHRAIN, SRI LANKA, AZERBAIJAN, AUSTRALIA, AUSTRIA, PHILIPPINES, TURKEY, RUSSIA, IRAN, IRAQ, CANADA, KOREA, JAPAN, YEMEN, FINLAND, ZIMBABWE, HUNGARY, PORTUGAL, VIETNAM, MOROCCO, THAILAND, SOUTH AFRICA, MEXICO, SINGAPORE, GREECE, KUWAIT, POLAND, NEW ZEALAND, SWEDEN, SWITZERLAND, BELGIUM, BHUTAN, BANGLADESH, TAIWAN, ROMANIA, CAMBODIA, KAZAKHSTAN, AFGHANISTAN.

