Alloy 42: Complete Properties & Application Guide

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Overview

Alloy 42 (UNS K94100 / W.Nr. 1.3917) is a nickel-iron alloy with a coefficient of thermal expansion matched to that of soft glass and ceramics. This makes it the preferred material for glass-to-metal seals in electronic packages and vacuum tubes.

Chemical Composition

The chemical composition of Alloy 42 is carefully controlled to achieve its unique combination of properties and performance characteristics.

Element	Min %	Max %
Iron (Fe)	Balance	Balance
Nickel (Ni)	40.0	43.0
Carbon (C)	—	0.05
Manganese (Mn)	—	0.80
Silicon (Si)	—	0.30
Chromium (Cr)	—	0.25
Aluminum (Al)	—	0.10

Mechanical Properties at Room Temperature

The mechanical properties of Alloy 42 vary depending on product form and heat treatment condition. The data below represents typical values for solution-annealed material.

Property	Value
Tensile Strength	550 MPa
Yield Strength (0.2% offset)	276 MPa
Elongation in 2 inches	33%
Density	8.12 g/cm3
Melting Point	1440 °C
Max Service Temperature	300 °C

Corrosion Resistance

Good atmospheric corrosion resistance. The alloy forms a tenacious oxide layer that promotes adhesion with glass during sealing. Not recommended for aggressive corrosive environments without protection.

Applications

The unique combination of properties makes Alloy 42 suitable for a wide range of demanding applications:

• Electronic Packaging: Glass-to-metal seals for hermetic electronic packages.
• Semiconductor: Leads and frames for integrated circuits.
• Vacuum Technology: Tubes and components requiring hermetic sealing.
• Lighting: Lead-in wires for lamps and vacuum tubes.
• Telecommunications: Waveguide components and coaxial cable seals.

Available Product Forms

Hangbo Alloy Group manufactures and supplies Alloy 42 in the following product forms, conforming to ASTM, AMS, and ASME specifications:

• Round Bars: Diameters from 6 mm to 300 mm, hot-finished or cold-drawn, solution annealed.
• Seamless Tubes & Pipes: Sizes from 6 mm OD to 219 mm OD, various wall thicknesses.
• Plates & Sheets: Thicknesses from 0.5 mm to 50 mm, hot-rolled or cold-rolled.
• Forgings: Custom flanges, rings, discs, and complex shapes per customer drawing.
• Welding Wire: Diameters 0.8 mm to 5.0 mm, precision-wound coils and spools.

Related Standards

Standard	Description
ASTM F30	Controlled Expansion Alloy
ASTM F1684	Low Expansion Alloy
AMS I-23011	Military Specification
DIN 17745	German Standard
GB/T 4339	Chinese Standard
JIS H2501	Japanese Standard

Contact Us for Alloy 42

Hangbo Alloy Group maintains extensive inventory of Alloy 42 in all standard product forms. We can provide mill test certificates, third-party inspection reports (SGS, TUV), and custom processing services.

For quotations, material certifications, or technical consultation, contact our sales team or call +86-136-1165-6360. We typically respond within 10 minutes.