4J36 Invar Wire For Thermostatic Applications Fe-Ni Alloy Wire With Controlled Thermal Expansion

4J36 Invar Wire for Thermostatic Applications | Fe-Ni Alloy Wire with Controlled Thermal Expansion

Product Overview

4J36 alloy wire, commonly known as Invar 36 wire, is a precision Fe-Ni alloy with an extremely low coefficient of thermal expansion (CTE). It contains approximately 36% nickel and is widely used in applications requiring dimensional stability across temperature changes, such as precision instruments, aerospace components, and electronic devices.

Material Composition

• Nickel (Ni): ~36%

• Iron (Fe): Balance

• Others: Trace amounts of Mn, Si, C, etc.

Thermal Expansion (20–100°C): ~1.0–1.5 × 10⁻⁶ /°C
Density: ~8.1 g/cm³
Resistivity: ~0.78 μΩ·m
Tensile Strength: ≥ 450 MPa
Magnetic Properties: Soft magnetic, stable under thermal cycling

Available Sizes

• Diameter: 0.02 mm – 3.0 mm

• Length: coil, spool, or cut-to-length as needed

• Surface: Bright, smooth, oxide-free

• Condition: Annealed or cold drawn

• Custom dimensions accepted

Key Features

• Extremely low thermal expansion

• Excellent dimensional stability

• Easy to weld and process

• High purity and oxidation resistance

• Vacuum compatible for sealed applications

• Custom packaging available

Applications

• Aerospace and satellite components

• Bimetallic thermostats and precision instruments

• Optical mounts and sensor elements

• Electronic device sealing and packaging

• Laser and infrared systems

• Measuring tools and calibration equipment

Packaging & Shipping

• Vacuum packaging, spools, or anti-rust film

• Air, sea, or express delivery available

• Lead time: 7–15 working days