4J50 Wire FeNi50 Alloy Wire ASTM F15 Soft Magnetic Sealing Wire for Glass to Metal Seals and Electronic Components
Product Description
4J50 wire is a precision iron-nickel soft magnetic alloy containing approximately 50% nickel and is equivalent to ASTM F15 standard. It is designed for applications requiring a close thermal expansion match with borosilicate glass and ceramic materials, making it ideal for glass-to-metal sealing.
This alloy wire offers excellent soft magnetic properties, good mechanical stability, and consistent thermal performance. It is widely used in electronic tubes, relays, vacuum devices, sensors, and microelectronic packaging. 4J50 wire is often referred to as a Kovar-type sealing material and is compatible with a wide range of high-reliability electronic and aerospace applications.
Key Features
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Matched thermal expansion to borosilicate hard glass
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Stable magnetic and mechanical performance
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Excellent glass-sealing and vacuum compatibility
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Smooth surface and high dimensional precision
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Good formability, weldability, and corrosion resistance
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Low outgassing for vacuum or hermetically sealed applications
Typical Applications
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Glass-to-metal sealed headers and pins
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Vacuum tubes, electronic relays, and sensors
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IC package leads and transistor enclosures
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Aerospace instrumentation and feedthroughs
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Medical electronics and hermetically sealed devices
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Thermal expansion matched sealing for glass/ceramic components
Chemical Composition (%)
| Element | Typical Content (%) |
|---|---|
| Nickel (Ni) | 49.0 – 51.0 |
| Cobalt (Co) | ≤ 0.50 |
| Manganese (Mn) | 0.30 – 0.60 |
| Silicon (Si) | ≤ 0.30 |
| Carbon (C) | ≤ 0.05 |
| Sulfur (S) | ≤ 0.02 |
| Phosphorus (P) | ≤ 0.02 |
| Iron (Fe) | Balance |
Mechanical Properties (Annealed Condition)
| Property | Typical Value |
|---|---|
| Tensile Strength | ≥ 450 MPa |
| Yield Strength (0.2%) | ≥ 250 MPa |
| Elongation | ≥ 30% |
| Hardness | ≤ 160 HV |
| Density | ~8.2 g/cm³ |
| Thermal Expansion (20–300°C) | ~5.0 × 10⁻⁶ /°C |
| Max Service Temp | ~500°C (932°F) |
Available Specifications
| Item | Details |
|---|---|
| Wire Diameter Range | 0.02 mm – 3.0 mm |
| Form | Spools, coils, cut lengths |
| Surface Finish | Bright, oxide-free, annealed |
| Standards | ASTM F15, GB/T 14986, YB/T 5231 |
| Condition | Annealed (soft), hard drawn |
| Packaging | Plastic spool 1 kg – 15 kg, vacuum packed available |
| Certification | ISO 9001, ROHS, EN 10204 3.1 |
| Country of Origin | China (OEM and logo customization available) |
Packaging & Shipping
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Vacuum packaging or plastic spools
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Anti-corrosion treatment
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Air/sea/express delivery available
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Delivery time: 7–15 business days
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![Huona Fecral 0cr25al5 High-Temperature Resistance Heating Round Wire]()
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