Our Kovar 4J29 Alloy Wire is a top-tier solution for glass-to-metal sealing in vacuum systems. With 29% nickel, 17% cobalt, and 54% iron, it delivers a CTE of ~5.0 ppm/°C (20-400°C), perfectly matching glass for airtight seals. It’s tough, corrosion-resistant, and built to handle the demands of precision applications. Whether you’re working on vacuum tubes or aerospace sensors, our 4J29 wire ensures your seals stay solid and reliable.
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The vacuum systems market is thriving, with a projected CAGR of 5.4% through 2032, driven by aerospace, electronics, and telecommunications advancements. Glass-to-metal seals are critical for vacuum tubes, microwave components, and sensors, where even slight thermal expansion can cause failures. The rise of 5G, satellite technology, and advanced electronics is pushing the need for reliable sealing materials like our 4J29 wire. It’s designed to meet these demands, offering precision and durability for high-stakes applications.
| 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 Kovar 4J29 Alloy Wire is a standout in vacuum system applications. It’s used in vacuum tubes for electronics, ensuring airtight seals that protect sensitive components. Microwave components, like waveguides and filters, rely on it for stable performance in telecommunications. In aerospace, it supports sensors and connectors that operate in extreme environments. Scientific instruments, such as mass spectrometers, also benefit from its reliability. Wherever hermetic sealing is critical, our 4J29 wire gets the job done.
Comparison Table: Kovar 4J29 vs. Alloy 42 (4J42) vs. 4J49 Fe-Ni-Cr
Parameter | Kovar 4J29 | Alloy 42 (4J42) | 4J49 Fe-Ni-Cr |
|---|---|---|---|
Composition | 29% Ni, 17% Co, 54% Fe | 42% Ni, 58% Fe | 42% Ni, 5% Cr, 53% Fe |
CTE (ppm/°C, 20-400°C) | ~5.0 | ~4.0–4.7 (20-300°C) | ~5.5 |
Temperature Range | -50°C to 400°C | -40°C to 300°C | -50°C to 450°C |
Curie Temperature | ~435°C | ~370°C | ~390°C |
Yield Strength (MPa) | ~345 | ~310 | ~345 |
Tensile Strength (MPa) | ~520 | ~520 | ~550 |
Density (g/cm³) | 8.36 | 8.12 | 8.20 |
Applications | Vacuum tubes, microwave components | Semiconductor lead frames, seals | Semiconductor packaging, vacuum tubes |
Oxidation Resistance | Excellent | Good | Excellent |
We know the market offers plenty of sealing alloys, but our Kovar 4J29 Alloy Wire stands out for its precision and quality. Our strict quality control ensures a consistent CTE and robust mechanical properties (yield strength ~345 MPa, tensile strength ~520 MPa). We provide customized wire sizes and forms to fit your exact specs, with faster delivery than many alternatives. Our efficient production process keeps costs low without compromising performance, and our alloy’s excellent CTE matching and corrosion resistance give it an edge in vacuum applications. With years of expertise, we’re your trusted partner for high-performance alloy solutions.
Why Choose Our Kovar 4J29 Alloy Wire?
Our Kovar 4J29 Alloy Wire is built for reliable glass-to-metal sealing in vacuum systems. Its precise thermal expansion, durability, and corrosion resistance make it perfect for vacuum tubes, aerospace sensors, and more. Whether you’re pushing the limits of 5G or building cutting-edge instruments, our wire ensures your components stay sealed and dependable. Contact us today to see how 4J29 can power your next project!
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
What is Kovar 4J29 Alloy Wire?
It’s a nickel-iron-cobalt alloy wire designed for reliable glass-to-metal sealing, perfect for vacuum systems requiring airtight performance.What are the key properties of Kovar 4J29?
It offers a CTE of ~5.0 ppm/°C (20-400°C), excellent corrosion resistance, and high mechanical strength, ideal for hermetic seals.What industries use Kovar 4J29 Alloy Wire?
Electronics, aerospace, telecommunications, and scientific instrumentation rely on it for stable sealing applications.What are common applications for Kovar 4J29?
It’s used in vacuum tubes, microwave components, aerospace sensors, and electronic connectors needing precise sealing.How does Kovar 4J29 compare to other sealing alloys?
Its Ni-Co-Fe composition provides a near-perfect CTE match with glass, ensuring superior seal reliability compared to many alloys.What temperature range is Kovar 4J29 effective in?
It maintains performance from -50°C to 400°C, ensuring dependable seals in vacuum and thermal environments.Is Kovar 4J29 weldable or machinable?
Yes, it’s weldable and machinable with standard techniques, though careful handling is needed due to its hardness.How does Kovar 4J29 align with industry trends?
It supports the demand for high-reliability sealing in vacuum systems, driven by advancements in aerospace, electronics, and 5G technology.
