Ferro-nickel

INVAR 36

FeNi36

UNS K93600 / K93601 / K93603

Invar 36 is an iron-nickel alloy (64% Fe / 36% Ni) recognized worldwide for its exceptional dimensional stability. Its name comes from the word “invariable,” referring to its near-total lack of expansion or contraction with temperature changes. Its coefficient of thermal expansion (~1.2 × 10⁻⁶/K) is among the lowest of all metals, making it indispensable in precision instruments, space-based optical structures, and aerospace composite molds.

Properties

Machinability
Weldability
Expansion rate

Development

BIOLOGY STANDARD

States

BIOLOGY STANDARD

Applications

Tools and Dies for Composite Forming
Cryogenic components

Chemical Composition

ElementFe (%)Neither (%)
Contents64.036.0

Mechanical Properties

Rm (MPa)≥520
0.2 Rp (MPa)≥340
A%≥42
Density (g/cm³)8.11

Available Sizes

Standards

ASTM F1684
AMS 7897

Certificate 3.1 available

Upon request when ordering

* These values are for reference only; they may vary depending on the standard and condition.