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Glass Sealing Precision Alloys Kovar Alloy 4J29 With Ceramic Wire / Rod / Strip

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China Ohmalloy Material Co.,Ltd certification
China Ohmalloy Material Co.,Ltd certification
I search for Nichrome plate long time, and successfully bought it from Ohmalloy material. OHMALLOY provide real good service in alloy service and can always help me in finding the correct resistance alloy.

—— Mike Harness

OHMALLOY can provie me only 1kg Kovar alloy wire 1.0mm with short time, that is really amazing. Thanks

—— Janey

Really professional in thermocouple wire and cable, what i want just can get from OHMALLOY

—— Chris

Enamelled Constantan 0.08mm, i never expect to get only 2kg of it. But OHMALLOY supply it to me with good quality. God Jesus! Such a reliable supplier from china

—— Aaron

Glass Sealing Precision Alloys Kovar Alloy 4J29 With Ceramic Wire / Rod / Strip

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Large Image :  Glass Sealing Precision Alloys Kovar Alloy 4J29 With Ceramic Wire / Rod / Strip Get Best Price

Product Details:
Place of Origin: China(Shanghai)
Brand Name: OHMALLOY
Certification: SGS, ISO
Model Number: 4J29
Payment & Shipping Terms:
Minimum Order Quantity: 30 KG
Price: negotiable
Packaging Details: Spool + Waterproof paper + Wooden case
Delivery Time: 25-35 working days
Payment Terms: L/C, D/A, D/P, T/T,
Supply Ability: 25000 KG per month
Detailed Product Description
Material: Fe Ni Co Alloy Condition: Soft
Wire Diameter Range: 0.1mm ~ 9.0mm Surface: Bright
Density: 8.27 G/cm3 Application: Sealing Material For Ceramics
High Light:

nickel iron alloy


fe ni alloy

Sealing Ceramic Vacuum Switch Fe Ni Co Alloy Ceramic - To - Metal



Ohmalloy-4J33 for Sealing and matching ceramics


OhmAlloy-4J33 (Expansion alloy)

(Common Name: 33НК, 4J33, KV-4, Ni33Co17)


4J33 alloy has a close Linear expansion coefficient with 95% Al2O3 ceramic in the range of -60 to 600 degrees Celsius. it is an Important sealing structural material in the electric vacuum industry; Mainly used for matching and ceramic sealing.


Normal composition%

Ni 32.0~33.6 Fe Bal. Co 14.0~15.2 Si ≤0.3
Mo - Cu - Cr - Mn ≤0.5
C ≤0.05 P ≤0.02 S ≤0.02    





Typical Physical properties

Density (g/cm3) 8.27
Electrical resistivity at 20(Ωmm2/m) 0.46
Thermal conductivity, λ/ W/(m*℃) 17.6
Curie point Tc/ 440
Elastic Modulus, E/ Gpa 139









The heat treatment process
Stress relief annealing Heating to 470~540℃. Keep 1~2h, cooling in the air
Annealing Heating to 750~ 900℃ In the medium vacuum
Holding time, h 15min. ~ 1 hour
cooling In the air


Coefficient of expansion

θ/℃ α1/10-6-1 θ/℃ α1/10-6-1
20~300 6.3 20~400 6.1
20~500 6.9 20~600 8.3




Typical Mechanical properties

Tensile Strength Elongation
Mpa %
539 32


Style of supply

Alloys Name Type Dimension  
OhmAlloy-4J33 Wire D= 0.1~8 mm  
OhmAlloy-4J33 Strip W= 5~250 mm T= 0.1 mm
OhmAlloy-4J33 Foil W= 10~100 mm T= 0.01~0.1 mm
OhmAlloy-4J33 Bar Dia= 8~100 mm L= 50~1000 mm


Glass Sealing Precision Alloys Kovar Alloy 4J29 With Ceramic Wire / Rod / Strip 0

Glass Sealing Precision Alloys Kovar Alloy 4J29 With Ceramic Wire / Rod / Strip 1




1. What's the minimum quantity customer can order?
If we have your size in stock, we can provide any quantity you want.
If we do not have, for spool wire, we can produce 1 spool, about 2-3kg. For coil wire, 25kg.

2. How can you pay for small sample amount?
We have account, wire transfer for sample amount also ok.

3. Customer do not have express account. How will us arrange the delivery for sample order?
Just need to provide your address information, we will check the express cost, you can arrange the express cost together with sample value.

4. What's our payment terms?
We can accept LC T/T payment terms, it also depending on delivery and total amount. Let's talk more in details after getting your detailed requirements.

5. Do you provide free samples?
If you want several meters and we have stock of your size, we can provide, customer need to bear the International express cost.

6. What's our working time?
We will give you reply through email/phone Online contact tool within 24 hours. No matter working day or holidays.

Contact Details
Ohmalloy Material Co.,Ltd

Contact Person: Mr. Qiu

Tel: +8613795230939

Send your inquiry directly to us