Iron Nickel Cobalt Alloy Rod/Bar Price | Supplier & Manufacturer

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Shanghai Metal Corporation is a leading Kovar Alloy (Fe-Ni-Co Alloy) manufacturer and supplier.

Kovar alloy, also known as Iron-Nickel-Cobalt alloy (typically 4J29), is a controlled-expansion alloy primarily composed of iron, nickel, and cobalt. It is specifically engineered to have a thermal expansion coefficient closely matching that of hard glass and ceramics. This alloy is widely applied in the aerospace, electronics, and vacuum industries for manufacturing glass-to-metal seals, transistor leads, integrated circuit packaging, and microwave tubes. By matching the thermal expansion of hard glass and ceramics, Kovar alloy prevents cracking and leaking caused by thermal stress during temperature fluctuations, ensuring the long-term reliability and airtightness of electronic components and vacuum devices. It effectively solves the critical problem of maintaining hermetic seals in high-precision environments.

If you want to know more about our categories (Kovar alloy, Fe-Ni-Co alloy, precision alloys) products or Kovar alloy price please feel free to contact us, we will reply you within 24 hours.

1. Material Composition: Iron (Fe) balance, Nickel (Ni) 28-30%, Cobalt (Co) 16-18% (Standard 4J29 / ASTM F15).

2. Product Forms: Supplied as bars, plates, strips, wires, and seamless tubes to suit different manufacturing processes.

3. Microstructure: Single-phase austenitic (FCC) structure, ensuring excellent ductility and stable thermal expansion curves.

4. Component Functions: Nickel stabilizes the austenitic phase to match hard glass; Cobalt lowers the Curie point and fine-tunes the thermal expansion coefficient.

5. Form-Based Applications: Strips and plates are used for IC lead frames and sealing shells; wires for transistor leads; tubes for microwave vacuum devices.

6. Core Performance: Provides a controlled low thermal expansion coefficient, preventing cracking and maintaining airtightness during temperature fluctuations.

1. Matched Thermal Expansion Provides a precisely controlled coefficient of thermal expansion (approx. 5.5×10⁻⁶/°C) that closely matches hard glass and ceramics, preventing thermal stress and cracking during temperature fluctuations to ensure reliable glass-to-metal seals.

2. Reliable Hermetic Sealing Forms a dense, adherent oxide film under recommended processing conditions (such as controlled pre-oxidation), creating strong chemical bonds with glass that significantly reduce leakage and packaging failures in electronic and vacuum devices.

3. Excellent Ductility and Formability Features a stable single-phase austenitic structure that allows for easy stamping, deep drawing, bending, and machining, enabling manufacturers to produce complex geometries like lead frames and sealing shells with reduced tool wear.

4. Stable Microstructure Maintains a stable austenitic phase without phase transformations from room temperature up to 400°C, ensuring long-term dimensional stability and consistent performance during both manufacturing and end-use operation.

5. Controlled Magnetic Properties Offers a predictable Curie temperature (around 435°C) and consistent magnetic permeability at room temperature, providing reliable performance for applications requiring specific magnetic behaviors or temperature-sensitive switching.

6. Good Corrosion Resistance Exhibits strong resistance to oxidation and atmospheric corrosion at ambient temperatures, protecting the integrity of the hermetic seal and extending the service life of critical components in harsh environments.

1. Integrated Circuit (IC) Packaging Used for sealing shells, lead frames, and glass-to-metal feedthroughs in microelectronic packages. It is ideal because its thermal expansion curve precisely matches hard glass and ceramics, preventing cracking and ensuring long-term hermeticity during thermal cycling. Recommended form: 4J29 strips and plates.

2. Microwave and Vacuum Tubes Applied in the manufacturing of envelopes, electrodes, and leads for high-power microwave tubes and X-ray tubes. It is suitable because it maintains excellent vacuum tightness and structural integrity under high-temperature operation, protecting sensitive internal components. Recommended form: Seamless tubes and fine wires.

3. Aerospace Sensors and Connectors Utilized in hermetic electrical connectors, pressure sensors, and gyroscope components for aircraft and satellites. It fits these scenarios because it withstands extreme temperature fluctuations without losing its sealing properties, ensuring critical safety and reliability in harsh environments. Recommended form: Machined bars and rods.

4. Medical Electronic Devices Employed in the airtight sealing of implantable devices (such as pacemakers) and diagnostic equipment (like X-ray tubes). It is the material of choice because it provides reliable, non-toxic, and zero-leakage encapsulation, protecting sensitive electronics from moisture and bodily fluids over long periods. Recommended form: Fine wires and thin strips.

Temper 4J29	Wire Tensile Strenght/MPa	Sheet Tensile Strenght/MPa

软态（S）	<585	<570
¼硬态（H¼）	585～725	520-630
½硬态（H½）	655～795	590-700
¾硬态（H¾）	725～860	600-770
硬态(H)	≥860	≥700

Typical Mechanical Properties:

Material	Condition	Yield Strength (0.1% Offset) psi	Elongation %
Alloy	Annealed	49,000	42
Yield Strength (0.1% Offset) MPa	Tensile Strength psi	Tensile Strength MPa
340	75,000	520

Parameters of Nickel Iron Cobalt Alloy Rod/Bar:

Diameter of ASTM F15 Alloy /Rod /Bar (inch)
0.04	0.187	0.5	0.1375
0.05	0.2	0.562	1.5
0.06	0.203	0.625	1.625
0.062	0.218	0.75	1.75
0.1	0.25	0.875	2
0.125	0.312	1	2.125
0.156	0.375	1.125	2.5
0.178	0.437	1.25	3
We can customize other sizes according to your requests

Standard Packaging

For Kovar alloy strips and wires: Each roll is wound on a standard spool or coil, wrapped with protective PE film, and secured with end caps. Rolls are then packed in reinforced export wooden cases with VCI anti-rust paper and desiccant to prevent moisture during ocean transit.

For Kovar alloy bars and plates: Products are bundled with steel straps, separated by wooden spacers, and placed on fumigated wooden pallets.

Specifics: Single roll weight up to 500kg; Wooden case dimensions can be customized up to 1200mm x 1000mm x 1000mm. Container load capacity is approximately 20-24 tons per 20GP.

Shipping

We support FCL and LCL sea freight, air freight, and express delivery depending on order quantity and destination. 【Optional trade terms include EXW / FOB / CIF, etc. Other terms may be available upon request.】

Shipping costs are calculated based on cargo volume, gross weight, destination, and selected transportation method.

Required shipping documents: Commercial Invoice, Packing List, Bill of Lading (B/L) or Air Waybill (AWB), and Mill Test Certificate (MTC).

Lead Time

Samples: 3–7 working days

Standard orders: 25–35 working days

Customized orders: 45–60 working days

1. How long does sample preparation take?

Samples are prepared within 3–7 working days. Custom dimensions or special surface treatments may require 7–10 working days.

2. What information do you need for a custom quotation?

Please provide: Material grade (e.g., 4J29), product form (strip, wire, bar, tube), exact dimensions (thickness/width/diameter), quantity, surface finish requirements, and tolerance standards.

3. What is the MOQ and production lead time?

MOQ is 100kg for standard sizes. Standard orders take 35–45 working days; customized orders take45–60 working days.

4. What is the difference between Kovar (4J29) and other Fe-Ni-Co alloys like 4J33?

4J29 is specifically designed to match hard glass and ceramics (CTE approx. 5.5×10⁻⁶/°C). 4J33 has a higher expansion coefficient (approx. 6.5×10⁻⁶/°C) and is used for sealing with different ceramics or soft glass. The choice depends strictly on the mating material's thermal expansion curve.

5. What factors should I consider when choosing Kovar alloy for glass-to-metal sealing?

You must consider the thermal expansion coefficient (CTE) match, the sealing temperature profile, the type of glass/ceramic, the controlled oxidation process to form the oxide layer, and the final hermeticity requirements.

6. What information do you need from me to recommend the right product?

Provide the specific mating glass or ceramic grade, the operating temperature range, the required product form (strip, wire, bar, or tube), and any mechanical property requirements (such as tensile strength or hardness).

Kovar Alloy / Iron Nickel Cobalt Alloy

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