Invar 36 / FeNi36 / 4J36 Alloy Precision Tubing

Invar 36 (FeNi36 / 4J36) Ultra-Low Expansion Precision Tubing | ZYTC Alloy

Invar 36, widely designated as FeNi36 or domestic grade 4J36, is a classic nickel-iron low-expansion precision alloy. Its most distinctive property is an extremely low coefficient of thermal expansion across normal and low-temperature working ranges, enabling nearly zero dimensional variation under temperature fluctuation. This unique physical characteristic makes Invar 36 precision tubing irreplaceable in high-precision industries that demand strict dimensional stability and zero thermal deformation.

Chemical Composition (Typical wt%)

Core Physical & Mechanical Properties

Key Material Features

• Ultra-low thermal expansion: Maintains stable dimensions from cryogenic temperature to 200°C, effectively eliminating structural deviation caused by temperature changes.
• Excellent dimensional stability: Resists thermal creep and micro-deformation, ideal for long-term high-precision measurement and optical equipment.
• Good low-temperature toughness: Retains stable mechanical performance in extreme low-temperature environments without brittleness failure.
• Reliable machinability: Supports precision cutting, bending and deep drawing for customized tubular structural parts.
• Antimagnetic property: Features low magnetic permeability, suitable for anti-magnetic watch and precision electronic component applications.

Professional Welding Guidelines

Invar 36 / 4J36 precision tubing has strict chemical sensitivity during welding. Uncontrolled welding heat input and mismatched filler materials will alter alloy composition, resulting in increased thermal expansion coefficient and reduced precision stability.

Applications

• Precision Instrumentation: Seismic creep gauges, precision scales, clock movement structural tubes and sensor housing components.
• Optoelectronic & Display Industry: TV shadow mask frames and fixed structural tubes to ensure stable imaging accuracy.
• High-Precision Surveying: Level staff tubular components for first-grade elevation surveying, replacing traditional unstable materials.
• Mechanical Engine Systems: Piston struts, motor valve precision tubes and thermal expansion limiting structural parts.
• Antimagnetic & High-End Electronics: Antimagnetic watch internal tubes and precision electronic component carriers.

ZYTC Alloy Manufacturing Advantages

ZYTC Alloy focuses on the production of high-precision low-expansion alloy tubes. Our Invar 36 / 4J36 precision tubing adopts vacuum smelting and multi-pass cold drawing processes, with precise annealing treatment to stabilize thermal expansion coefficient and internal microstructure.