Invar 36 (UNS K93600)
Invar 36 (UNS K93600, FeNi36, ASTM F1684) is an iron–nickel alloy of roughly 36% nickel, the composition at which thermal expansion falls to its minimum. Near room temperature it moves less than almost any other metal, which is why it is specified for precision instruments, metrology fixtures, optical benches, composite layup tooling, laser cavities and LNG containment, wherever a dimension has to hold while the temperature does not.
Available Forms
Equivalent Grades & Designations
| Property | Value |
|---|---|
| UNS number | K93600 / K93601 / K93602 / K93603 |
| Werkstoff / EN number | 1.3912 |
| EN designation | Ni36 |
| Density | 8.1 g/cm3 |
| Melting range | 1430 °C |
| Specific heat capacity (20 °C) | 486 J/kg·K |
| Thermal conductivity (20 °C) | 12.8 W/m·K |
| Electrical resistivity (20 °C) | 78 µΩ·cm |
| Modulus of elasticity (20 °C) | 143 GPa |
| Curie temperature | 230 °C |
Identifiers and physical constants for Invar 36. A dash means no such designation is published for this grade.
Specifications by Product Form
Invar 36 (K93600 / K93601 / K93602 / K93603) is supplied to a different standard in each form. Quote the one that matches the product you are ordering.
| Product form | Specification |
|---|---|
| Plate, sheet and strip | ASTM F1684 / B753 / B603 |
| Rod and bar | ASTM F1684 |
| Wire | ASTM B603 |
| Pipe and tube | Mill specification |
Aurico Alloys LLP supplies Invar 36 across the forms above, with material test certificates (EN 10204 3.1) and export-ready packaging from Mumbai, India. Contact us for stock availability and pricing.