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4j29 Ni29co17 Kovar WIRE Precision Alloy Invar36 4j42 Iron Nickel Constant Expansion WIRE

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4j29 Ni29co17 Kovar WIRE Precision Alloy Invar36 4j42 Iron Nickel Constant Expansion WIRE

Name: 4j29 Ni29co17 Kovar WIRE Precision Alloy Invar36 4j42 Iron Nickel Constant Expansion WIRE
Brand: HUONA
Price: 12.00 USD

Brand Name : HUONA

Model Number : WIRE

Certification : ISO9001

Place of Origin : CHINA

MOQ : 1KG

Price : US$12.00-45.00

Payment Terms : T/T

Supply Ability : 1000kg Per Week

Delivery Time : WEEK

Packaging Details : 1500tons/Year

Model NO. : Expansion Alloy

HS Code : 7505220000

Purity : Alloy

Specification : Customized

Origin : Jiangsu, China

Production Capacity : 1500tons/Year

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Kovar Alloy Wire Material 4j29 Ni29co17 Kovar WIRE Precision Alloy Invar36 Nilo42 4j42 Iron Nickel Constant Expansion WIRE

Product Introduction – 4J29 Alloy Wire Rod (Kovar Equivalent)

4J29, also known as Kovar in international standards, is a Nickel–Iron–Cobalt controlled expansion alloy engineered for glass-to-metal and ceramic-to-metal sealing. Its thermal expansion closely matches that of hard glass and alumina ceramics, making it an ideal material for hermetic packaging, vacuum electronics, and aerospace components.

As a wire rod, 4J29 is supplied in spooled wire, straight rods, or custom-cut lengths, with tight dimensional tolerances and excellent surface finish.

Technical Specifications:

Property	Value
Alloy Name	4J29 (Equivalent to Kovar)
Chemical Composition	Ni: ~29%, Co: ~17%, Fe: Balance
CTE (30–300°C)	~5.0 × 10⁻⁶ /°C
Density	~8.3 g/cm³
Tensile Strength	450–750 MPa (annealed)
Yield Strength	≥ 300 MPa
Elongation	≥ 25%
Electrical Resistivity	~0.42 μΩ·m
Thermal Conductivity	~17 W/m·K
Melting Range	~1450–1500°C
Wire Rod Diameter Range	0.1 mm – 6.0 mm (custom sizes available)
Condition	Annealed / Bright / Oxidized / Pickled
Packaging	Coils, straight rods, spool, or custom-cut

Industry	Application Examples
Electronics	Transistor cans, relay headers, integrated circuit housings
Optoelectronics	TO headers, photodiode cases, laser housings
Aerospace	Hermetic sensors, thermal control components
Vacuum Electronics	Tube components, getter assemblies
Medical Devices	Sealed implantable components, bio-safe hermetic packaging
Telecom	Fiber optic connectors, microwave & RF sealing elements
Defense	Hermetically sealed sensors and modules

Product Overview – 4J42 Alloy (Low Expansion Alloy)

4J42 is a Nickel-Iron alloy designed to have a low coefficient of thermal expansion (CTE). It is primarily used in applications that require precise dimensional stability across temperature variations, making it ideal for glass-to-metal sealing, ceramic-to-metal sealing, and high-precision electronic components.

This alloy is typically used in industries such as aerospace, electronics, and telecommunications, where the thermal expansion properties of materials are critical to maintaining the functionality and reliability of components.

Precision alloys are metal materials with special physical properties (such as magnetic, electrical, thermal and other properties). The vast majority of precision alloys are based on ferrous metals, and only a few are based on non-ferrous metals. Usually include magnetic alloys (see magnetic materials), elastic alloys, expansion alloys, thermal bimetals, electrical alloys, hydrogen storage alloys (see hydrogen storage materials), shape memory alloys, magnetostrictive alloys (see magnetostrictive materials), etc.

Industry	Application Examples
Electronics	Glass-to-metal seals for vacuum tubes, transistor cans, semiconductor housings
Aerospace	Seals for sensors, connectors, and components in aerospace systems
Telecommunications	Microwave and RF components, fiber optic connectors, satellite components
Medical Devices	Hermetic sealing for implantable devices and bio-compatible sensors
Automotive	Automotive electronic sensor housings, connectors, and precision seals
Vacuum Systems	Vacuum tube components, electrical contacts

Property	Value

Alloy Name

4J42 (Nickel-Iron Alloy)

Chemical Composition

Ni: ~42%, Fe: Balance

CTE (20–100°C)

~4.7 × 10⁻⁶ /°C

Density

~8.2 g/cm³

Tensile Strength

450–700 MPa (annealed)

Yield Strength

≥ 300 MPa

Elongation

≥ 20%

Hardness

~160 HV (annealed)

Electrical Resistivity

~0.48 μΩ·m

Magnetic Properties

Magnetic at room temperature

Melting Range

~1450°C

Wire Diameter Range

0.10 mm – 6.0 mm (custom sizes available)

Surface Finish

Bright / Annealed / Oxidized

Packaging

Spools, coils, or custom lengths

Soft magnetic alloys are a class of alloys with high permeability and low coercivity in weak magnetic fields. According to the different elements that make up the alloy, it can be divided into electromagnetic pure iron (industrial pure iron), iron-silicon alloy, iron-nickel alloy, iron-aluminum alloy, iron-silicon-aluminum alloy and iron-cobalt alloy, etc.1J06,1J12,1J17,1J18,1J22,1J30,1J36,1J38,1J46,1J50,1J51,1J54,1J76,1J77,1J79,1J80,1J85,1J87

Permanent magnet alloy not only has high hardness and mechanical properties, but also has strong anti-demagnetization ability, high coercivity value (greater than 20kA/m), magnetic "hard" and other characteristics, so it is also called hard magnetic alloy.2J04,2J07,2J09,2J10,2J31,2J53,2J84,2J85Elastic alloys include high elastic alloys and constant elastic alloys. It is used to make elastic elements such as elastic sensitive elements, energy storage elements and frequency elements in precision instruments.3J01,3J21,3J53Expansion alloys(Invar Alloy) are divided into Kovar alloys, ceramic sealing alloys, low expansion alloys, and constant expansion alloys. Widely used in electronic industry, precision measuring tools, precision instruments and low temperature engineering and other fields.4J28,4J29,4J32,4J33,4J36,4J40,4J42,4J50
Precision alloys with nickel, chromium, aluminum and iron as the main components, the resistivity is about three times higher than that of manganese copper, and has a lower temperature coefficient of resistance and low thermal potential to copper, with good long-term resistance stability and resistance. Oxidation properties.
It is suitable for making precision resistance elements in various measuring instruments and meters, making precision micro-resistance elements and strain

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