Our 4J49 Fe-Ni-Cr Alloy Bar is a top-tier choice for high-performance glass-to-metal sealing in electronic devices. With 42% nickel, 5% chromium, and 53% iron, it delivers a CTE of ~5.5 ppm/°C (20-450°C), perfectly matching glass for airtight seals. It’s tough, corrosion-resistant, and built to handle the rigors of precision electronics. Whether you’re working on semiconductor packaging or medical sensors, our 4J49 bar ensures your seals stay strong and reliable.

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The electronics industry is booming, with a projected CAGR of 6.1% through 2032, driven by 5G, IoT, and medical device advancements. Glass-to-metal seals are critical for hermetic packaging in semiconductors, microwave components, and sensors, where thermal stability is a must. As devices get smaller and more complex, materials like our 4J49 bar are in high demand for their ability to maintain seal integrity under stress. We’re ready to meet these trends, delivering alloys that power the next wave of electronic innovation.

Elements		4J29	4J36
Carbon (C)	Not greater than	0.03	0.05
Sulfur (S)		0.02	0.02
Phosphorus (P)		0.02	0.02
Manganese (Mn)		≤0.50	0.20-0.60
Silicon (Si)		≤0.30	≤0.30
Nickel (Ni)		28.5-29.5	35.0-37.0
Chromium (Cr)		-	-
Cobalt (Co)		16.8-17.8	-
Iron (Fe)		Rest	Rest
Other Elements

Alloy Grade	20°C-100°C	20°C-300°C	20°C-500°C
4J36 Invar Alloy	1.2×10⁻⁶ /°C	2.5×10⁻⁶ /°C	-
4J29 Kovar Alloy	4.6×10⁻⁶ /°C	5.5×10⁻⁶ /°C	6.2×10⁻⁶ /°C

Alloy Grade	4J36 Invar Alloy	4J29 Kovar Alloy
Density (g/cm³)	8.1	8.2
Tensile Strength (MPa)	500-600	600-700
Yield Strength (MPa)	250-350	300-400
Hardness (HV)	150-200	200-250

Alloy Grade	4J36 Invar Alloy	4J29 Kovar Alloy
Electrical Resistivity (10⁻⁶ Ω·cm)	80	50
Thermal Conductivity (W/m·K)	10-12	16-18

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Our 4J49 Fe-Ni-Cr Alloy Bar is a standout in electronic applications. It’s used in vacuum tubes and semiconductor packaging, ensuring airtight seals for sensitive components. Microwave components, like waveguides and filters, rely on its stability for telecommunications. Medical devices, such as implantable sensors, benefit from its durable, biocompatible seals. Aerospace electronics also use it for connectors and sensors in extreme environments. Wherever precision sealing is critical, our 4J49 bar delivers.

Comparison Table: 4J49 Fe-Ni-Cr vs. 4J33 Ni-Co vs. Kovar 4J29

Parameter	4J49 Fe-Ni-Cr	4J33 Ni-Co	Kovar 4J29
Composition	42% Ni, 5% Cr, 53% Fe	35% Ni, 17% Co, 48% Fe	29% Ni, 17% Co, 54% Fe
CTE (ppm/°C, 20-450°C)	~5.5	~4.7	~5.0
Temperature Range	-50°C to 450°C	-40°C to 450°C	-50°C to 400°C
Curie Temperature	~390°C	~430°C	~435°C
Yield Strength (MPa)	~345	~340	~345
Tensile Strength (MPa)	~550	~520	~520
Density (g/cm³)	8.20	8.27	8.36
Applications	Semiconductor packaging, vacuum tubes	Semiconductor packaging, vacuum tubes	Vacuum tubes, microwave components
Oxidation Resistance	Excellent	Excellent	Excellent

We know the market offers plenty of sealing alloys, but our 4J49 Fe-Ni-Cr Alloy Bar stands out for its quality and performance. Our strict quality control ensures a consistent CTE and robust mechanical properties (yield strength ~345 MPa, tensile strength ~550 MPa). We provide customized bar sizes and forms to fit your exact needs, with faster delivery than many alternatives. Our efficient production process keeps costs low without sacrificing quality, and our alloy’s excellent CTE matching and corrosion resistance give it an edge in electronic applications. With years of expertise, we’re your trusted partner for high-performance alloy solutions.

Why Choose Our 4J49 Fe-Ni-Cr Alloy Bar?

Our 4J49 Fe-Ni-Cr Alloy Bar is built for the future of electronics. Its precise thermal expansion, durability, and corrosion resistance make it perfect for semiconductor packaging, medical sensors, and more. Whether you’re pushing the limits of 5G or building life-saving devices, our bar ensures your components stay sealed and reliable. Contact us today to see how 4J49 can power your next project!

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About Us:

Our 12,000㎡ factory is equipped with complete capabilities for research, production, testing, and packaging. We strictly adhere to ISO 9001 standards in our production processes, with an annual output of 1,200 tons. This ensures that we meet both quantity and quality demands. Furthermore, all products undergo rigorous simulated environment testing including high temperature, high pressure, and corrosion tests before being dispatched, ensuring they meet customer specifications. For all our clients, we offer timely and multilingual after-sales support and technical consulting, helping you resolve any issues swiftly and efficiently.

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FAQs

1. What is 4J49 Fe-Ni-Cr Alloy Bar?
   It’s a nickel-iron-chromium alloy bar designed for high-performance glass-to-metal sealing, ideal for electronic devices needing airtight reliability.

2. What are the key properties of 4J49?
   It offers a CTE of ~5.5 ppm/°C (20-450°C), excellent corrosion resistance, and high mechanical strength, perfect for hermetic seals.

3. What industries use 4J49 Alloy Bar?
   Electronics, telecommunications, aerospace, and medical device industries rely on it for robust sealing solutions.

4. What are common applications for 4J49?
   It’s used in vacuum tubes, semiconductor packaging, microwave components, and medical sensors requiring precise seals.

5. How does 4J49 compare to other sealing alloys?
   Its Ni-Cr-Fe composition ensures a precise CTE match with glass, offering superior seal durability compared to many alloys.

6. What temperature range is 4J49 effective in?
   It performs reliably from -50°C to 450°C, maintaining seal integrity in demanding electronic environments.

7. Is 4J49 weldable or machinable?
   Yes, it’s weldable and machinable with standard techniques, though careful control is needed to prevent work hardening.

8. How does 4J49 align with industry trends?
   It supports the demand for miniaturized, high-reliability components in 5G, IoT, and medical electronics, driven by technological advancements.