Alloy 42 / UNS K94100 / 4J42 Precision Nickel Iron Alloy
Source：http://www.zytcsteel.com Time：2026/9/23 14:50:11 View：
ZYTC Alloy is a professional Chinese manufacturer and supplier of high-precision Alloy 42 (UNS K94100 / 4J42) nickel-iron expansion alloy. As a classic low-expansion precision alloy with 42% nickel content, 4J42 is specially engineered to deliver a thermal expansion coefficient closely matched with soft glass, hard ceramics and silicon materials. It is widely adopted for hermetic sealing, electronic packaging, lead frames and precision structural components in the electronics, semiconductor and optical industries.
Alloy 42 features stable dimensional performance under continuous high-temperature service up to 400°C, ensuring airtight and vacuum-tight sealing integrity for long-term operation. Supplied in diversified rolling and drawing states including hot rolled, cold drawn, annealed, 1/4H, 1/2H and full hard temper, it fully meets diverse precision stamping, bending and machining requirements. With reliable expansion stability and consistent batch quality, Alloy 42 / 4J42 has become the preferred material for standard electronic sealing projects globally.
Key Product Advantages
-
Precise Thermal Expansion Matching: Perfectly compatible with soft glass, ceramic and silicon substrates, eliminating sealing cracking and air leakage risks.
-
Stable High-Temperature Performance: Maintains stable structural size and sealing performance at working temperatures up to 400°C.
-
Multiple Temper States Available: Supports annealed soft state and various cold-rolled hardness states for flexible processing from stamping to precision forming.
-
Strict Dimension Consistency: Ultra-precise strip and foil tolerance control, suitable for miniature electronic precision parts manufacturing.
-
Professional Usage Guidance: Low machinability requires surface plating for corrosion protection; we recommend 4J29 Kovar alloy for hard borosilicate glass sealing scenarios.
Chemical Composition (Typical, wt%)
ZYTC Alloy strictly controls raw material smelting to ensure ultra-clean composition and uniform microstructure for stable expansion performance.
|
Element
|
Ni
|
Fe
|
C
|
Mn
|
Si
|
P
|
S
|
Cr
|
|---|---|---|---|---|---|---|---|---|
|
Content
|
41.0–43.0
|
Balance
|
≤0.05
|
≤0.80
|
≤0.30
|
≤0.02
|
≤0.02
|
≤0.15
|
Typical Mechanical & Physical Properties (Annealed State)
|
Performance Parameter
|
Standard Value
|
|---|---|
|
Yield Strength (0.2% Offset)
|
285 MPa (41.3 ksi)
|
|
Tensile Strength
|
510 MPa (74 ksi)
|
|
Elongation at Break
|
35%
|
|
Hardness
|
145 HB / 78 HRB
|
|
Elastic Modulus
|
145 GPa (21 Msi)
|
|
Density
|
8.12 g/cm³
|
|
Melting Point
|
1425°C (2597°F)
|
|
Max Service Temperature
|
400°C
|
|
Formability Rating
|
85 (Excellent)
|
|
Machinability Rating
|
35 (Low, plating recommended)
|
Available Product States & Specifications
As a professional precision alloy manufacturer, ZYTC Alloy supplies Alloy 42 / 4J42 in diversified forms and hardness temper states to meet full-cycle production needs:
-
Product Forms: Precision strip, thin foil, sheet, bar and custom profiles
-
Temper States: Annealed, CR-1/4H, CR-1/2H, CR-H cold rolled, hot rolled, cold drawn
-
Custom Service: Precision slitting, cutting, surface finishing and size customization
Applications
-
Glass & ceramic hermetic sealing components
-
Semiconductor and electronic packaging parts
-
Electronic lead frames and precision terminal components
-
Silicon substrate matching structural parts
-
High-precision instrument and optical device accessories
ZYTC Alloy Manufacturing Strength
We implement full-process quality control for Alloy 42 precision alloys, from vacuum smelting, precise rolling and heat treatment to finished product inspection. Every batch undergoes strict dimensional tolerance testing, mechanical performance verification and expansion coefficient detection. We provide complete MTR certificates, stable batch consistency, flexible MOQ and fast global delivery, supporting customer projects from prototype trial production to large-scale mass production.
Get Custom Quote
Looking for high-precision Alloy 42 / 4J42 nickel iron expansion alloy strips, foils or bars? Send your size requirements, temper states and application scenarios. ZYTC Alloy's professional technical team will provide tailored solutions and competitive quotations within 24 hours.
Contact ZYTC Alloy Today
📧 Email: dominic@zytc-steel.com
📲 WhatsApp: +86 13132148618