Glass Sealing Alloy Wire 4J28 Fe-Ni Alloy Wire Soft Magnetic Material

Product Name:
Glass-Sealing Alloy Wire 4J28 | Fe-Ni Alloy Wire | Soft Magnetic Material

Material:
4J28 (Fe-Ni Alloy, Kovar-type Glass-Sealing Alloy)

Specifications:
Available in various diameters (0.02 mm to 3.0 mm), lengths customizable

Applications:
Glass-to-metal sealing, electronic tubes, sensors, vacuum components, and other precision electronic devices

Surface Treatment:
Bright surface, oxide-free, annealed or cold-drawn

Packaging:
Coil/Spool form, plastic wrapping, vacuum-sealed bag or customized packaging upon request

Product Description:

4J28 alloy wire, also known as Fe-Ni alloy wire, is a precision soft magnetic and glass-sealing material. With a composition primarily consisting of iron and approximately 28% nickel, it provides exceptional thermal expansion matching with borosilicate glass, making it widely used in electronic packaging and glass-to-metal sealing applications.

4J28 wire exhibits excellent sealing properties, stable magnetic performance, and reliable mechanical characteristics. It is extensively used in electronic tubes, hermetic packaging, semiconductor housings, and high-reliability aerospace and military components.

Features:

• Excellent Glass-to-Metal Sealing: Ideal thermal expansion compatibility with borosilicate glass for tight, hermetic seals

• Good Magnetic Properties: Suitable for soft magnetic applications and stable magnetic response

• High Dimensional Precision: Available in ultra-fine diameters, precision-drawn for sensitive electronic components

• Oxidation Resistance: Bright surface, oxidation-free, suitable for vacuum and high-reliability sealing

• Customizable: Dimensions, packaging, and surface conditions can be tailored to specific customer needs

Applications:

• Electronic tubes and vacuum devices

• Glass-to-metal sealed relays and sensors

• Semiconductor and hermetic packages

• Aerospace and military-grade electronic components

• Optical and microwave components requiring precise thermal expansion matching

Technical Parameters:

• Chemical Composition:

  • Ni: 28.0 ± 1.0%

  • Co: ≤ 0.3%

  • Mn: ≤ 0.3%

  • Si: ≤ 0.3%

  • C: ≤ 0.03%

  • S, P: ≤ 0.02% each

  • Fe: Balance

• Density: ~8.2 g/cm³

• Thermal Expansion Coefficient (30–300°C): ~5.0 × 10⁻⁶ /°C

• Melting Point: Approx. 1450°C

• Electrical Resistivity: ~0.45 μΩ·m

• Magnetic Permeability (μ): High at low magnetic field intensities

• Tensile Strength: ≥ 450 MPa

• Elongation: ≥ 25%

Packaging & Shipping:

• Packaging:
  Plastic spools, vacuum bags, anti-rust wrapping, and customized labels upon request

• Shipping Methods:
  Air freight, sea freight, express delivery

• Lead Time:

• 
  7–15 working days based on order quantity

Huona (Shanghai) New Material Co., Ltd. Was established in 2008, currently have three divisions: Magnesium Division, Thermal Spray Division and Functional Material Division.

Magnesium Division produces magnesium metal products. Various models of high-quality magnesium alloy plate, magnesium rods, high-purity magnesium, magnesium plate, magnesium die casting, magnesium extrusion profiles and other metal magnesium and deep processing products.

Thermal spray wire Division offers a wide variety of pure metal and metal alloy wires, including nickel-, iron-, aluminum-, and zinc-based wires for thermal spray projects.

Fuctional Material Division supply electronic packaging COMPONENTS(GTMS, CTMS), soft magnetic alloys and bimetal strip.

Our company is certified by ISO9001 quality system and ISO14001 environmental protection system.

Mission Statement

We try our best to understand and utilize information within the environment. With this competency, we assist customers to create added value and contribute to the development of industry and healthy living.

We strive for "Best, " welcome challenges, and are relentless till we deliver products and solutions.