4J32 alloy wire is a precision nickel-iron alloy with a low and controlled coefficient of thermal expansion, specifically designed for glass-to-metal sealing applications. With approximately 32% nickel, this alloy provides excellent compatibility with hard glass and borosilicate glass, ensuring reliable hermetic sealing in electronic vacuum devices, sensors, and military-grade packages.
Nickel (Ni): ~32%
Iron (Fe): Balance
Minor elements: Manganese, Silicon, Carbon, etc.
Thermal Expansion (30–300°C): ~5.5 × 10⁻⁶ /°C
Density: ~8.2 g/cm³
Tensile Strength: ≥ 450 MPa
Resistivity: ~0.45 μΩ·m
Magnetic Properties: Soft magnetic behavior with stable performance
Diameter: 0.02 mm – 3.0 mm
Length: in coils, spools, or cut-to-length as required
Condition: Annealed or cold drawn
Surface: Bright, oxide-free, smooth finish
Packaging: Vacuum-sealed bags, anti-rust foil, plastic spools
Excellent match with glass for hermetic sealing
Stable low thermal expansion performance
High purity and clean surface for vacuum compatibility
Easy to weld, shape, and seal under various processes
Customizable size and packaging options for different applications
Glass-to-metal sealed relays and vacuum tubes
Sealed electronic packages for aerospace and defense
Sensor components and IR detector housings
Semiconductor and optoelectronic packaging
Medical devices and high-reliability modules