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4J29 Rod Kovar Alloy Bar Fe Ni Co Controlled Expansion Alloy for Glass to Metal Sealing

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4J29 Rod Kovar Alloy Bar Fe Ni Co Controlled Expansion Alloy for Glass to Metal Sealing

Name: 4J29 Rod Kovar Alloy Bar Fe Ni Co Controlled Expansion Alloy for Glass to Metal Sealing
Brand: HUONA
Price: 1 USD

Brand Name : HUONA

Model Number : 4J29

Certification : ISO 9001, SGS, RoHS

Place of Origin : CHINA

MOQ : 1KG

Price : Negptiation

Payment Terms : T/T

Supply Ability : 10000kg/week

Delivery Time : a week

Packaging Details : Wooden case, steel strip bundling

Diameter : 3 mm – 200 mm

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

Origin : China (OEM/ODM service available)

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Product Description

4J29 alloy rod, also known as Kovar rod, is a Fe-Ni-Co controlled expansion alloy with a thermal expansion coefficient closely matching that of hard glass and ceramics. It provides excellent glass-to-metal and ceramic-to-metal sealing properties, ensuring reliable hermeticity.

With stable mechanical performance, good machinability, and outstanding sealing reliability, 4J29 rods are widely applied in electronic packaging, vacuum devices, semiconductor bases, sensors, and aerospace instruments.

4J29 Rod Kovar Alloy Bar Fe Ni Co Controlled Expansion Alloy for Glass to Metal Sealing

Key Features

Fe-Ni-Co controlled expansion alloy
Thermal expansion matches hard glass and ceramics
Excellent hermetic sealing performance
Stable mechanical strength at different temperatures
High machinability and surface finish
Available in rods, wires, sheets, and customized forms

Typical Applications

Glass-to-metal hermetic sealing
Semiconductor packaging bases
Electronic packaging components
Vacuum tubes and light bulbs
Aerospace and defense devices
Sensors, relays, and feedthroughs

Chemical Composition (%)

Element	Content
Fe	Balance
Ni	~29%
Co	~17%
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

4J29 Rod Kovar Alloy Bar Fe Ni Co Controlled Expansion Alloy for Glass to Metal Sealing

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