Industrial metal background

Invar 36 Plate (UNS K93600 / ASTM F1684 / W.Nr. 1.3912)

Special AlloysSheet/Plate
invar36

Overview

Invar 36 (also known as Nilo 36, Pernifer 36, FeNi36) is an iron-nickel alloy containing approximately 36% nickel. It is renowned for its extremely low coefficient of thermal expansion (CTE) — approximately one-tenth that of carbon steel at room temperature. This unique property makes Invar 36 the benchmark material for applications requiring exceptional dimensional stability across temperature variations.

Description (English)

Coefficient of Thermal Expansion (CTE) 20 – 100°C (68 – 212°F)//CTE (ppm/°C)1.2 – 1.3 20 – 200°C (68 – 392°F)//CTE (ppm/°C)2.0 – 2.5 20 – 300°C (68 – 572°F)//CTE (ppm/°C)5.5 – 6.5 20 – 400°C (68 – 752°F)//CTE (ppm/°C)8.0 – 9.0 20 – 500°C (68 – 932°F)//CTE (ppm/°C)11.0 – 12.0

Size Range

  • Thickness:0.5 mm – 100 mm (0.020" – 4") — up to 150 mm custom
  • Width:500 mm – 1,500 mm (20" – 60") Length 1,000 mm – 3,000 mm (40" – 120")
  • Length:1,000 mm – 3,000 mm (40" – 120")

Grade Specification

SystemValue
🇺🇸 UNSK93600 / K93601
🇺🇸 ASTMF1684 (plate), AMS I-23011
EN / DIN1.3912
AFNORFeNi36
🇬🇧 BSNILO 36
🇯🇵 JIS— (supplied to ASTM)
🇨🇳 GB4J36 (expansion alloy)
TrademarksInvar®, Nilo®, Pernifer®, FeNi36

Chemical Composition

ElementValue
Ni35.0 – 37.0
C≤ 0.05
Si≤ 0.30
Mn≤ 0.60
P≤ 0.025
S≤ 0.025
Cr≤ 0.25
Co≤ 0.25
FeBalance

Mechanical Properties

productCenter.propertyValue
Tensile Strength Rm440 – 550 MPa (64 – 80 ksi)
0.2% Yield Strength240 – 310 MPa (35 – 45 ksi)
Elongation A (50 mm)30 – 45%
Reduction in Area55 – 70%
Hardness125 – 160 HB
Impact KV2 (room temp)80 – 120 J

Physical Properties

PropertyUnitValue
Densityg/cm³8.05 g/cm³ (0.291 lb/in³)
Melting Point°C~1,430 °C (2,606 °F)
Modulus of ElasticityGPa141 GPa (20.5 × 10⁶ psi)
Shear Modulus-52 GPa
Poisson's Ratio-0.29
Thermal Conductivity (20°C)W/m·K10.5 W/(m·K)
Specific Heat (20°C)J/kg·K0.515 J/(g·K)
Electrical Resistivity (20°C)μΩ·cm0.82 μΩ·m
Curie Temperature-~277 °C (531 °F) — above this, magnetic properties are lost and CTE increases
Magnetism-Ferromagnetic (below Curie temperature)

Applications

  • Precision Instruments & Metrology
  • Aerospace & Defense
  • Electronics & Semiconductors
  • Cryogenic & LNG
  • Industrial