MachineU > China Products > Minerals & Metallurgy
4J28 Rod / Bar | Kovar Alloy Rods for Glass-to-Metal Sealing Applications
4J28 Rod / Bar | Kovar Alloy Rods for Glass-to-Metal Sealing Applications
Specifications
Brand Name :
HUONA
Model Number :
Bar
Certification :
ISO 9001, SGS, RoHS
Place of Origin :
china
MOQ :
5kg
Price :
negotiation
Payment Terms :
T/T
Supply Ability :
1000kg a week
Delivery Time :
1 week
Packaging Details :
Wooden case, steel strip bundling
Density :
~8.2 g/cm³
Thermal Expansion (20–400°C) :
~5.0 ×10⁻⁶/°C
Tensile Strength :
≥ 450 MPa
Working Temp :
-196°C to 450°C
Diameter :
3 mm – 200 mm
Description

Product Description

4J28 alloy rod is an iron-nickel-cobalt (Fe-Ni-Co) controlled expansion alloy specially designed for glass-to-metal and ceramic-to-metal sealing applications. It has a linear expansion coefficient that precisely matches hard glass and ceramics, ensuring reliable hermetic sealing.

With stable mechanical strength, excellent machinability, and outstanding sealing performance, 4J28 rods are widely used in electronic packaging, vacuum devices, semiconductor components, and aerospace instruments.

4J28 Rod / Bar | Kovar Alloy Rods for Glass-to-Metal Sealing Applications

Key Features

  • Fe-Ni-Co alloy with controlled thermal expansion

  • Excellent sealing performance with glass and ceramics

  • Stable mechanical strength at various temperatures

  • Easy machining and surface treatment

  • Reliable long-term hermeticity

  • Available in rods, wires, sheets, and customized forms

Typical Applications

  • Glass-to-metal hermetic sealing

  • Electronic packaging components

  • Vacuum tubes and light bulbs

  • Semiconductor packaging bases

  • Aerospace and defense devices

  • Sensor housings and feedthroughs

Chemical Composition (%)

Element Content
Fe Balance
Ni ~28%
Co ~18%
Minor Elements Mn, Si, C, etc.

Physical and Performance Properties

Property Typical Value
Density ~8.2 g/cm³
Thermal Expansion (20–400°C) ~5.0 ×10⁻⁶/°C
Tensile Strength ≥ 450 MPa
Hardness ~HB 140–170
Working Temp -196°C to 450°C
Standard GB/T, ASTM, IEC

Available Specifications

Item Range
Diameter 3 mm – 200 mm
Length ≤ 6000 mm
Tolerance As per ASTM / GB standard
Surface Bright / Polished / Black
Packaging Wooden case, steel strip bundling
Certification ISO 9001, SGS, RoHS
Origin China (OEM/ODM service available)

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



4J28 Rod / Bar | Kovar Alloy Rods for Glass-to-Metal Sealing Applications
4J28 Rod / Bar | Kovar Alloy Rods for Glass-to-Metal Sealing Applications
4J28 Rod / Bar | Kovar Alloy Rods for Glass-to-Metal Sealing Applications
4J28 Rod / Bar | Kovar Alloy Rods for Glass-to-Metal Sealing Applications

Send your message to this supplier
Send Now

4J28 Rod / Bar | Kovar Alloy Rods for Glass-to-Metal Sealing Applications

Ask Latest Price
Watch Video
Product Detail
Brand Name :
HUONA
Model Number :
Bar
Certification :
ISO 9001, SGS, RoHS
Place of Origin :
china
MOQ :
5kg
Price :
negotiation
Contact Supplier
video
4J28 Rod / Bar | Kovar Alloy Rods for Glass-to-Metal Sealing Applications

Huona (Shanghai) New Material Co., Ltd.

Verified Supplier
1 Years
shanghai, shanghai
Since 2008
Business Type :
Manufacturer, Exporter
Main Products :
Low Expansion Alloy, Soft Magnetic Alloy, Elastic Alloy
Total Annual :
8000000-100000000
Employee Number :
100~120
Certification Level :
Verified Supplier
Discover similar products
View More

Find Similar Products By Category:

Supplier Homepage Products Low Expansion Alloy
MachineU China Products Minerals & Metallurgy
Contact Supplier
Submit Requirement