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Controlled Expansion Kovar Alloy 1.3981 4j29 Precision Alloy

Place of Origin China
Brand Name DLX
Model Number 4j29(kovar)
Minimum Order Quantity 50
Price $20-$45
Packaging Details Wooden Case&PP tube
Delivery Time 7-21 days
Payment Terms L/C, T/T, Western Union, MoneyGram
Supply Ability 300 tons per month

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Product Details
Certificate ISO9001 Shape Bar
Ni (Min) 28.5 Size Customized
Color Nickel,silver Ultimate Strength (≥ MPa) 570
Elongation (≥ %) 30 % Application Glass To Metal Sealing
Brand Name DLX

Kovar Precision Alloy


1.3981 Nickel Iron


4j29 Precision Alloy

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Product Description

Controlled Expansion Kovar Alloy 1.3981 4j29 Precision Alloy 0

Controlled Expansion Kovar Alloy 1.3981 4j29 Precision Alloy 1

  • Precision alloy iron nickel cobalt W.Nr 1.3981 kovar alloy 4J29 bar



Precision Alloy Kovar alloy is a vacuum melted, iron-nickel-cobalt alloy that is widely used in the electronics industry. Precision Alloy Kovar is a nickel-iron-cobalt, controlled-expansion alloy which contains 29% nickel. Precision Alloy its coefficient of expansion, which decreases with rising temperature to the inflection point, matches the expansion rate of borosilicate glasses and alumina ceramics.

Precision Alloy Kovar alloy has been used for making hermetic seals with the harder Pyrex glasses and ceramic materials. This Precision alloy has found wide application in power tubes, microwave tubes, transistors, and diodes. In integrated circuits, Precision Alloy has been used for the flat pack and the dual-in-line package.


Basic performance: Precision Alloy is divided into low-expansion alloy and fixed-expansion alloy, the latter is also known as sealing alloy. Precision Alloy Expansion alloy besides has the specific thermal expansion coefficient, according to the different USES also requires a good sealing property, weldability and corrosion resistance, machinability and cutting, and in the use of expansion characteristics caused by the temperature range there is no obvious change of phase transformation, Precision Alloy product is commonly bar, sheet, strip, wire and tube and so on.
Precision Alloy Expansion alloy applications: Precision Alloy is widely used in glass, metal and ceramic sealing in avionics and instruments, electric vacuum industry and other electronic devices, electric light source and other fields.







Chemical Composition

Grade C% P% S% Mn% Si% Cu% Cr% Mo% Ni% Co% Fe%
Kovar Max 0.03 Max 0.020 Max 0.020 Max 0.50 Max 0.30 Max 0.20 Max 0.20 Max 0.20 28.5-29.5 16.8-17.8 Bal.



Grade UNS Werkstoff Nr.
Kovar K94610 1.3981


Physical Properties

Grade Density Melting Point
Kovar 8.17 g/cm3 1449°C


Mechanical Properties

Grade Tensile Strength N/mm²
Soft 1/4 Hard 1/2 Hard 3/4 Hard Full Hard
Kovar Strip <570 520-630 590-700 600-770 >700
Kovar Wire <585 585-725 655-795 725-860 >860


Coefficient of Expansion

Alloy Linear Coefficient of Thermal Expansion a,10-6/°C
20-200°C 20-300°C 20-400°C 20-450°C 20-500°C 20-600°C 20-700°C 20-800°C
Kovar 5.9 5.3 5.1 5.3 6.2 7.8 9.2 10.2


Controlled Expansion Kovar Alloy 1.3981 4j29 Precision Alloy 2Controlled Expansion Kovar Alloy 1.3981 4j29 Precision Alloy 3Controlled Expansion Kovar Alloy 1.3981 4j29 Precision Alloy 4Controlled Expansion Kovar Alloy 1.3981 4j29 Precision Alloy 5