Special AlloysSheet/Plate

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
| System | Value |
|---|---|
| 🇺🇸 UNS | K93600 / K93601 |
| 🇺🇸 ASTM | F1684 (plate), AMS I-23011 |
| EN / DIN | 1.3912 |
| AFNOR | FeNi36 |
| 🇬🇧 BS | NILO 36 |
| 🇯🇵 JIS | — (supplied to ASTM) |
| 🇨🇳 GB | 4J36 (expansion alloy) |
| Trademarks | Invar®, Nilo®, Pernifer®, FeNi36 |
Chemical Composition
| Element | Value |
|---|---|
| Ni | 35.0 – 37.0 |
| C | ≤ 0.05 |
| Si | ≤ 0.30 |
| Mn | ≤ 0.60 |
| P | ≤ 0.025 |
| S | ≤ 0.025 |
| Cr | ≤ 0.25 |
| Co | ≤ 0.25 |
| Fe | Balance |
Mechanical Properties
| productCenter.property | Value |
|---|---|
| Tensile Strength Rm | 440 – 550 MPa (64 – 80 ksi) |
| 0.2% Yield Strength | 240 – 310 MPa (35 – 45 ksi) |
| Elongation A (50 mm) | 30 – 45% |
| Reduction in Area | 55 – 70% |
| Hardness | 125 – 160 HB |
| Impact KV2 (room temp) | 80 – 120 J |
Physical Properties
| Property | Unit | Value |
|---|---|---|
| Density | g/cm³ | 8.05 g/cm³ (0.291 lb/in³) |
| Melting Point | °C | ~1,430 °C (2,606 °F) |
| Modulus of Elasticity | GPa | 141 GPa (20.5 × 10⁶ psi) |
| Shear Modulus | - | 52 GPa |
| Poisson's Ratio | - | 0.29 |
| Thermal Conductivity (20°C) | W/m·K | 10.5 W/(m·K) |
| Specific Heat (20°C) | J/kg·K | 0.515 J/(g·K) |
| Electrical Resistivity (20°C) | μΩ·cm | 0.82 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

