4J29 Kovar Alloy Sheet for Glass-to-Metal Sealing ASTM F15

Brand Name:HUONA
Certification:ISO9001
Model Number:PLATE
Minimum Order Quantity:1KG
Delivery Time:WEEK
Payment Terms:T/T
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Location: Shanghai Shanghai China
Address: 1900 Mudanjiang Road, Baoshan District, 201999, Shanghai, China
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Product Description

4J29 alloy sheet, also known internationally as Kovar alloy (UNS K94610, ASTM F15), is a nickel-iron-cobalt alloy with controlled thermal expansion characteristics. It is widely used in hermetic sealing applications due to its precisely matched coefficient of expansion with hard glass and ceramics.

The alloy maintains dimensional stability across a wide temperature range, making it ideal for use in electronic components requiring tight tolerances and vacuum integrity. Typical applications include glass-to-metal seals in transistors, vacuum tubes, integrated circuits, microwave packages, and optical housings.

Available in cold-rolled or annealed condition, 4J29 sheets offer excellent workability, uniform grain structure, and high surface finish for precision forming and sealing processes.

Key Features

  • Matched thermal expansion with borosilicate and aluminosilicate glasses

  • Excellent hermeticity and vacuum sealing performance

  • Stable mechanical properties across temperature ranges

  • Easily machined, deep drawn, or stamped

  • Good oxidation resistance in air

  • Compliant with ASTM F15 and GB/T 14986 standards

Typical Applications

  • Hermetic glass-to-metal seals

  • Electronic packaging (IC, transistor, diode headers)

  • Microwave devices and optical components

  • Relay housings, vacuum tubes, and sensor shells

  • Aerospace and communication electronics

Chemical Composition (%)

ElementContent (%)
Nickel (Ni)29.0 ± 1.0
Cobalt (Co)17.0 ± 1.0
Iron (Fe)Balance
Silicon (Si)≤ 0.3
Manganese (Mn)≤ 0.5
Carbon (C)≤ 0.05
Chromium (Cr)≤ 0.2
Phosphorus (P)≤ 0.015
Sulfur (S)≤ 0.015
Aluminum (Al)≤ 0.1
Copper (Cu)≤ 0.2

Mechanical Properties (Annealed)

PropertyTypical Value
Tensile Strength≥ 450 MPa
Yield Strength≥ 300 MPa
Elongation (L=50 mm)≥ 20%
Hardness (HV)≤ 200 HV
Density8.3 g/cm³
Coefficient of Expansion5.0 × 10⁻⁶ /°C (30–400°C~)
Melting Range1450 – 1500°C
Electrical Resistivity~0.42 μΩ·m

Available Specifications

ItemDetails
Thickness Range0.05 mm – 5.0 mm (custom sizes available)
WidthUp to 600 mm (slit widths available)
LengthUp to 3000 mm (or coils upon request)
Surface FinishBright, Cold-Rolled, Ground, or Annealed Matte
ToleranceThickness: ±0.01 mm; Width: ±0.5 mm (custom precision available)
Delivery ConditionAnnealed / Stress Relieved / Pickled
PackagingVacuum sealed + export wooden case; rust-preventive wrap included
CertificationISO 9001 / Material Certificate (EN 10204 3.1/3.2) / RoHS / REACH
Country of OriginChina (OEM support available)

Optional Services:

  • Custom stamping or laser cutting

  • Surface cleaning for vacuum applications

  • Pre-punched or slotted formats

  • Cleanroom packaging





China 4J29 Kovar Alloy Sheet for Glass-to-Metal Sealing ASTM F15 supplier

4J29 Kovar Alloy Sheet for Glass-to-Metal Sealing ASTM F15

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