Alloy 36 / NILO® 36 / Invar 36 – Properties, Applications and Technical Data
Alloy 36, also known as NILO® 36 and Invar 36, is a binary nickel-iron alloy with approximately 36% nickel. The material is best known for its very low coefficient of thermal expansion around room temperature, making it ideal for applications where dimensional stability is crucial.
The alloy is used, among other things, for tools for composites in the aerospace industry, length standards, tape measures and meters, precision components and pendulum and thermostat rods. It is also used as a low-expansion component in bimetallic strips, in cryogenics and for laser and optics-related components.
Properties of Alloy 36 / NILO® 36
Alloy 36 (UNS K93600 / K93601, Werkstoffnr 1.3912) combines low thermal expansion with good machinability and stability in precision applications. The low expansion is particularly true in the room temperature range, making the material well suited for measuring and reference components as well as fixtures and tools where tolerances must be maintained over time.
- Type: Nickel-iron alloy with low thermal expansion
- Alloy: Ni-Fe (~36% Ni) (Alloy 36 / NILO® 36 / Invar 36)
- Structure: Austenitic structure (Ni-Fe)
- Designations: Alloy 36, NILO® 36, Invar 36, UNS K93600 / K93601, Werkstoffnr 1.3912
Advantages
- Very low thermal expansion around room temperature
- High dimensional stability in precision applications
- Suitable for tools and fixtures for composite materials
- Well-known and proven alloy for measuring and reference components
- Can be used in cryogenic applications where stability is important
Limitations
- Not intended for high corrosion loads without the right environment/surface treatment
- The low expansion is mainly optimized around room temperature (not for all temperature ranges)
- Magnetic properties can be a factor in some applications (ferromagnetic at room temperature)
Typical applications
Aerospace & composite tools
Tools, fixtures and molds for composite materials where low expansion provides better tolerance control.
Measurement & reference components
Length standards, tape measures, gauges and precision parts.
Precision engineering
Components where dimensional stability is critical over time and temperature.
Cryotechnology & optics
Low expansion components in cryogenic systems, laser and optics applications.
Thermal expansion
Alloy 36 is particularly well known for its low coefficient of thermal expansion (CTE) around room temperature. This makes the material suitable where small dimensional changes can affect function, fit or measurement accuracy.
Environments where Alloy 36 performs well:
- Applications requiring low thermal expansion around room temperature
- Precision technology, measurement and reference components
- Composite tools where tolerances must be maintained during temperature changes
- Cryogenic applications where dimensional stability is important
Environments to avoid:
- Highly corrosive environments without the right material choice/surface treatment
- Applications where very low expansion is required far outside the alloy's optimal temperature range
Technical data
| Alternative name |
Invar 36 |
| UNS |
K93600 / K93601 |
| Werkstoffnr |
1.3912 |
| Nickel content |
~36% |
| Density |
~8.1 g/cm³ |
| Modulus of elasticity |
~141 GPa |
| Coefficient of thermal expansion (20–100°C) |
~1.2 x 10⁻⁶ /°C |
| Melting point |
~1430°C |
| Electrical resistivity |
~0.8 µΩ·m |
| Magnetic properties |
Ferromagnetic at room temperature |
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Contact us if you need technical advice or would like a quote – we will help you find the right material for your application.
Buy Alloy 36 / NILO® 36 from HARALD PIHL – your specialist in special alloys with global delivery.
Our strengths
- Certified quality management: ISO 9001
- Aviation & Defense: AS9120 and meets defense sector requirements
- Full traceability and material certificate according to EN 10204 3.1
- Material according to ASTM, ASME, AMS and ISO standards
- Complies with AD 2000 and PED (Pressure Equipment) guidelines
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