4.5*112*85mm FeNi42 alloy plate with Permanent Expansion in bright
surface
Ohmalloy Material Co.,Ltd is a high-tech enterprise which specialized in making all kinds of
alloy such as high resistance alloy, low-resistance copper nickel
alloy, precision alloy, FeCrAl alloy and thermocouple Alloy.
Ohmalloy Material Co.,Ltd have a full production line from melting, surface cleaning,
rolling and slitting, full set of testing machine and can meet all
kinds of technical requirement from customer. Our product is widely
used in heating equipment, big steel mill, mineral, electrical
equipment, food machinery, auto industry, aerospace industry. Our
product not only is popular in domestic market, but also been
exported to all over the world.
Our company aims to be the best-quality alloy producer in the
world. We insist on developing the more advanced alloy strip
technology, to serve all the customer, improve people’s living
level, make a more green earth in the future

OhmAlloy-4J42 (Expansion alloy)
(Common Name: 42H Glass Sealing 42, Nilo42, N42, FeNi42)
4J42 alloy is mainly composed of iron, nickel elements. It is
characterized with a fixed coefficient of expansion. Increase the
thermal expansion coefficient and the Curie point with increase of
nickel content.
4J42 alloy is widely used the structure of the sealing material in
the electric vacuum industry.
Normal composition%
Ni | 41.5~42.5 | Fe | Bal. | Co | - | Si | ≤0.3 |
Mo | - | Cu | - | Cr | - | Mn | ≤0.8 |
C | ≤0.05 | P | ≤0.02 | S | ≤0.02 | Al | ≤0.1 |
Typical Physical properties
Density (g/cm3) | 8.12 |
Electrical resistivity at 20℃(Ωmm2/m) | 0.61 |
Thermal conductivity, λ/ W/(m*℃) | 14.6 |
Curie point Tc/ ℃ | 360 |
Elastic Modulus, E/ Gpa | 147 |
Coefficient of expansion
θ/℃ | α1/10-6℃-1 | θ/℃ | α1/10-6℃-1 |
20~100 | 5.6 | 20~400 | 5.9 |
20~200 | 4.9 | 20~450 | 6.9 |
20~300 | 4.8 | 20~500 | 7.8 |
20~350 | 4.95 | 20~600 | 9.2 |
Typical Mechanical properties
Tensile Strength | Elongation |
Mpa | % |
490 | 35 |
The heat treatment process |
Annealing | Heated to 900 ±20℃ in a hydrogen atmosphere |
Holding time, h | 1 hour |
cooling | With speed not more than 5 ℃ / min. cooling to below 200 ℃ |
Style of supply
Alloys Name | Type | Dimension |
OhmAlloy-4J42 | Wire | D= 0.1~8mm |
OhmAlloy-4J42 | Strip | W= 5~250mm | T= 0.1mm |
OhmAlloy-4J42 | Foil | W= 10~100mm | T= 0.01~0.1 |
OhmAlloy-4J42 | Bar | Dia= 8~100mm | L= 50~1000
|

FAQ
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 we 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.How do you guarantee the quality?
We have QC who are responsible for tracking and monitoring whole
production process, and we are willing to accept customer‘s
testing.
7. What's our working time?
We will give you reply through email/phone Online chat tool within
24 hours. No matter working day or holidays.