• Huona (Shanghai) New Material Co., Ltd.
    Alfred***
    We received the goods, everything went fine. Perfect packaging, good product quality, good price - we are satisfied.
  • Huona (Shanghai) New Material Co., Ltd.
    May***
    The product quality is very good, beyond my expectations, the actual use of fully meet my needs, we will buy again.
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    I bought low expansion alloy from Joy, She is a very responsible lady, Huona's products quality is pretty good.
Contact Person : Roy
Phone Number : +86 18930254719
WhatsAPP : +8618930254719

4J29 (Kovar) Precision Fe-Ni-Co Glass-to-Metal Sealing Alloy Wire for Hermetic Seals, Electronic Components, Vacuum Devices, Connectors and Aerospace Applications

Place of Origin Shanghai
Brand Name Huona
Certification ISO9001, SGS, and so on
Model Number 4J29
Minimum Order Quantity negotiation
Price negotiation
Packaging Details Spool + Carton + Wooden Case
Delivery Time 7-20days
Payment Terms T/T
Supply Ability 100 Tons per year
Product Details
Max Continuous Operating Temperature(℃) 450℃ Resisivity(μΩ·m) 0.49 μΩ·m
Density(g/m³) 8.17 Thermal Conductivity (W/m·K, 20°C) 17.3
Tensile Strength(N/m㎡) 490-690mpa Melting Point(℃) 1450℃
Hardness(Hv) 140-220Hv Elongation(%) ≥20%
Highlight

4J29 Kovar alloy Fe-Ni-Co controlled expansion alloy 29HK ASTM F15

,

low thermal expansion matching thermal expansion coefficient glass-to-metal hermetic sealing

,

stable microstructure compact oxide film mercury resistant

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Product Description

4J29 Alloy Wire (Kovar Wire) is a precision iron-nickel-cobalt low-expansion sealing alloy designed for glass-to-metal sealing applications. It offers excellent thermal expansion compatibility, good mechanical strength, and reliable hermetic sealing performance. Its coefficient of thermal expansion closely matches that of hard glass and borosilicate glass over a specified temperature range, making it an ideal material for Glass-to-Metal Seals (GTMS).

The alloy wire features excellent cold workability, weldability, dimensional stability, and consistent surface quality. Manufactured under strict chemical composition control and optimized heat treatment processes, 4J29 wire provides stable microstructure, reliable performance, and high production consistency.

4J29 alloy wire is widely used in aerospace, military, electronics packaging, vacuum devices, relays, sensors, RF connectors, integrated circuit packages, power feedthroughs, cable sealing assemblies, and other hermetically sealed electrical and electronic components requiring long-term reliability.

Various wire diameters, coil or straight wire forms are available. Customized dimensions, tolerances, surface finishes, and packaging can also be provided according to specific customer requirements.


1. Chemical Composition:

Ni

28.5-29.5

C

≤0.03

Fe

Bal

Co

16.8-17.8


2. Technical  Specifications:

Parameter

Specification

Max continuous Operating Temperature(℃)

450℃

Resisivity(μΩ·m)

0.49 μΩ·m

Density(g/m³)

8.17

Thermal Conductivity (W/m·K, 20°C)

17.3

Tensile strength(N/m㎡)

490-690mpa

Melting point(℃)

1450℃

Hardness(Hv)

140-220Hv

Elongation(%)

≥20%

 

3. Production Attributes

Product Form

4J29 wire

Diameter

customization

Surface Finish

Bright, Polished

Packaging Type

Coil, Bundle, Straight Rods

Certification

ISO9001, SGS, and so on

Application Environment

Chemical, Industrial,Home


4.Applications

  • Glass-to-Metal Seals (GTMS)
  • Hermetic Connectors
  • Electrical Feedthroughs
  • Cable Sealing Components
  • Hermetic Cable Assemblies
  • Electronic Packaging
  • Semiconductor Packages
  • Integrated Circuit (IC) Packages
  • Vacuum Tubes
  • Vacuum Electronic Devices
  • Relays
  • Reed Switches
  • Pressure Sensors
  • Temperature Sensors
  • RF & Microwave Connectors

5.Key features

  • Excellent matching thermal expansion (core advantage)
  • Stable metallurgical structure
  • Standard chemical composition (Fe-Ni-Co controlled expansion alloy
  • Good mechanical & processing performance
  • 4J29 (Kovar) Precision Fe-Ni-Co Glass-to-Metal Sealing Alloy Wire for Hermetic Seals, Electronic Components, Vacuum Devices, Connectors and Aerospace Applications 0