Alloy 48, also known as Invar 48, is a nickel-iron alloy distinguished by its very low coefficient of thermal expansion, slightly higher than that of Alloy 42 but still notable for precision applications. Alloy 48 is recognized under various designations and standards, including NILO 48, UNS K94800, DIN 1.3922, FE-NI48, A48, and W.NR. 1.3922. These designations reflect its broad acceptance and compliance with diverse industry standards.

This alloy typically contains about 48% nickel with the remainder primarily being iron. The specific combination of these elements provides a very low thermal expansion rate, making Alloy 48 ideal for applications where precise dimensional stability is required despite temperature variations.

Alloy 48 Sheet | Plate

Alloy 48 sheets and plates are available in various thicknesses and sizes, designed to provide high dimensional stability and flatness. These forms are essential in precision manufacturing and are commonly used in high-tech sectors such as aerospace, telecommunications, and precision instrumentation, where exact dimensions are critical.

Alloy 48 Round Bar | Rod

Alloy 48 round bars and rods come in a range of diameters and lengths, suitable for machining into custom parts. These components are important for mechanical linkages, structural elements, and various fittings that must maintain dimensional integrity despite temperature changes. Their stability under thermal fluctuations makes them ideal for precision-engineered parts.

Alloy 48 Strip | Coil

Available in flexible strips and coils, Alloy 48 is used for applications requiring materials to be bent, formed, or used continuously. These products are particularly valuable in the manufacture of springs, connectors, and other components where both flexibility and dimensional stability are crucial. They find applications in automotive, electronics, and high-precision machinery.

Alloy 48 Applications

• Glass-to-metal seals for electronic tubes and hermetic devices.

Alloy 48 Properties

• Coefficient of Thermal Expansion: Approximately 1.2 x 10^-6 /°C, making Alloy 48 highly suitable for applications requiring extremely low thermal expansion.
• Density: Around 8.2 g/cm³, providing an optimal balance of strength and weight for various industrial applications.
• Thermal Conductivity: Approximately 14-16 W/m·K, offering moderate heat conduction while ensuring dimensional stability.
• Magnetic Properties: Generally ferromagnetic, which can be a critical consideration for applications where magnetic interference needs to be managed.
• Mechanical Properties: Alloy 48 provides good strength and ductility, engineered primarily for maintaining dimensional precision rather than maximum mechanical strength.

Machining Alloy 48

• Cutting: Alloy 48 can be cut using conventional tools. It is important to use sharp tools and adjust cutting speeds to avoid excessive wear and achieve smooth cuts.
• Drilling: For drilling Alloy 48, high-speed steel (HSS) drills or carbide-tipped bits are recommended. Proper lubrication and cooling are essential to prolong tool life and ensure clean, accurate holes.
• Turning: Carbide inserts are preferred for turning Alloy 48. Consistent feed rates and effective heat management are crucial to maintaining dimensional accuracy during the turning process.
• Milling: Alloy 48 can be milled effectively using conventional techniques. Employ carbide end mills and cooling fluids to control heat and prevent dimensional distortions during milling.
• Grinding: Grinding Alloy 48 is ideal for achieving tight tolerances and fine surface finishes. Use suitable abrasive wheels and coolant to ensure a high-quality finish and preserve dimensional integrity.

Chemical Composition

• Nickel (Ni): Min 48%
• Chromium (Cr): Max 0.25%
• Manganese (Mn): Max 0.80%
• Silicon (Si): Max 0.30%
• Carbon (C): Max 0.05%
• Aluminum (Al): Max 0.10%
• Phosphorus (P): Max 0.025%
• Sulfur (S): Max 0.025%
• Iron (Fe): Balance