4J36 alloy products
Material Family / Precision

4J36

Invar 36 — Fe-Ni alloy with near-zero thermal expansion for precision instruments and cryogenic service.

Introduction

§01 — General

4J36 (Invar 36) is an iron-nickel alloy exhibiting exceptionally low thermal expansion coefficient (≈1.3 × 10⁻⁶/°C) from cryogenic temperatures to 230°C. It is the essential material for precision instrument components, optical benches, LNG tank membranes and composite tooling where dimensional stability under temperature variation is critical.

ASTM F1684GB/T 14986AFNOR NF A54-301

Quick Facts

Density
8.1 g/cm³
Max Service Temp
230°C
Series
Precision

Available Product Forms

§02 — Forms
WireStripBar & RodPlate & Sheet

Key Characteristics

§03 — Features
Near-zero thermal expansion (α ≈ 1.3 × 10⁻⁶/°C)
Invar 36 standard
Cryogenic to 230°C range
Dimensional stability champion
LNG tank membrane material

Typical Uses

§04 — Applications
Precision optical benches and mounts
LNG carrier tank membranes
Composite material tooling
Laser and optical cavities
Cryogenic transfer line components

Frequently Asked Questions

4J36 FAQ

What is 4J36 used for?

4J36 is a Precision alloy used in Precision optical benches and mounts, LNG carrier tank membranes, Composite material tooling. It offers Near-zero thermal expansion (α ≈ 1.3 × 10⁻⁶/°C) and Invar 36 standard.

What is the chemical composition of 4J36?

4J36 is a controlled-composition Precision alloy supplied to ASTM F1684 and GB/T 14986. We provide the full mill test certificate with heat-specific chemistry on request.

What forms is 4J36 available in?

4J36 is regularly supplied in Wire, Strip, Bar & Rod, Plate & Sheet. Custom forms and dimensions available on request.

What is the maximum service temperature of 4J36?

4J36 is rated for service up to 230°C. Contact our metallurgy team for specific application recommendations.

Need 4J36 material?

Request a quote with your specification — grade, form, dimensions and quantity.

Request a Quote
Add RAS Alloy as a preferred source on Google