Invar 36 Supplier
City Special Metals is the UK’s leading stockist and supplier of high-performance, specialist alloys, including all varieties of Invar 36 (FeNi36).
Available in many forms, we can offer a bespoke solution that meets your exact requirements and specification for your Invar 36 application, be it from Plate, Bar, Sheet, Coil or Wire. With over 20 years’ experience, our team has a combined wealth of knowledge about Invar 36 and its different characteristics, so we can guarantee you will find the product that fits your requirements.
For pricing or general advice speak to CSM today on +44 (0) 1909 519 189, email sales@cityspecialmetals.com or complete the contact form below.
Invar 36 Stock
Invar 36 (FeNi36) is a nickel-iron, low-expansion alloy that exhibits a near-zero rate of thermal expansion and can maintain almost constant dimensions from cryogenic temperatures to 260°C. It has become a popular choice for composite material manufacturing.
Invar Material
Invar 36 is commonly identified by the designation UNS K93600 and the European 1.3912 material number. Relevant specifications may include ASTM F1684, DIN 17745, MIL-I-23011 Class 7 and MIL-S-16598, depending on the required product form, composition and condition. Please speak to our team to confirm material availability and certification against a particular specification.
Some other industry terms for the alloy include NILO 36, Pernifer 36 and Carpenter Invar 36, depending on the manufacturer.
| Product Form | Range From | Range To | |
|---|---|---|---|
 | Invar Plate | 4mm | 400mm |
 | Invar Round Bar | 4mm | 500mm |
 | Invar Square Bar | 70mm | 400mm |
 | Invar Flat Bar | N/A | 250mm x 250mm |
 | Invar Sheet & Coil | 0.025mm | 3.175mm |
 | Invar Wire | 0.15mm | 3.5mm |
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Invar 36 Properties
- Dimensional Stability
Between – 100°C & 260°C - Durability
Strong performance, toughness, and resilience - Near-Zero
Coefficient of linear thermal expansion - Flexibility
Good workability, weldability and easy-to-machine
Invar 36 Applications
- Moulds and lay up tools for composites
- Devices, electrical transformers, and circuit breakers
- Precision equipment elements as such: lasers, measuring and positioning devices, thermostats, precision condenser blades
- High voltage transmission lines
Invar 36 Markets
- Aerospace
- Optical Laser Systems
- Semiconductor Manufacture
- Telecommunications
- Scientific
- Electronic
Invar 36 Composition
| Mechanical Properties | ||
|---|---|---|
| Metallurgical Condition | Annealed, Descaled | |
| Yield Strength | KSI (MPa) | 38 (260) Max |
| Tensile Strength | KSI (MPa) | 63 (430) Max |
| Hardness | HB | 135 |
| Elongation | 50mm | >30% (Typical 40%) |
| Co Efficient of Thermal Expansion | ||
|---|---|---|
| 30-350°C | 10-6/°C | 4.8 |
| 30-400°C | 10-6/°C | 7.5 |
| Density | g/cm³ | 8.13 |
| Curie Temp | °F (°C) | 446 230 |
| Melting Point | °F (°C) | 2462 1450 |
| Modulus of Elasticity at 20°C | MPa | 145000 |
| Youngs/Shears Modulus | MPa | 57000 |
| Specific Heat at 20°C | J/g- °C | 0.51 |
| Thermal Conductivity at 20°C | J/cm.s.°C | 0.105 |
| Poisson’s coefficient | 0.25 |
| Technical Specifications | ||
|---|---|---|
| ASTM | UNS | Werkstoff |
| F1684 | K93603 | 1.3912 |
| Chemistry | ||
|---|---|---|
| Nickel | Ni | 35.5 – 36.5 |
| Iron | Fe | Balance |
| Carbon | C | 0.01 max |
| Silicon | Si | 0.2 max |
| Manganese | Mn | 0.2 – 0.4 |
| Sulphur | S | 0.002 max |
| Phosphorus | P | 0.07 max |
| Chromium | Cr | 0.15 max |
| Cobalt | Co | 0.5 max |
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We can distribute metals across the globe, including locations in Europe, The Middle East, The Far East and the Americas.
Phone Us
+44 1909 519 189
Speak to the Sales Team
sales@cityspecialmetals.com
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info@cityspecialmetals.com
More about Invar
Invar 36 was discovered in 1896, by Charles Edouard Gullaume whilst working with the International Bureau of Weights and Measures. Its unique property of low and linear expansion over a wide temperature range allowed the production of an effective bimetal which could be used in safety cut-off devices for gas cookers and heaters. For his work on the nickel-iron system and the discovery of Invar, Charles Edouard Guillaume was awarded a Nobel Prize for Physics early in the 20th century.
Invar is also known by the following trade names;
- Invar ®
- Invar 36 ®
- Pernifer 36®
- Dilaton 36®
- Nilo 36®
- Ametek 936®
- ATI 36®
- NI 36®
- FeNi36
Invar 36 FAQs
What is Invar 36, and what are its key properties?
Invar 36 is a nickel–iron alloy containing around 36% nickel and 64% iron. It is best known for its exceptionally low coefficient of thermal expansion, meaning it changes very little in size when temperatures fluctuate. This property makes it ideal for precision applications where dimensional stability is essential. The alloy is machinable but may require stress-relief or annealing to maintain accuracy after fabrication.
What are the typical applications of Invar 36?
Invar 36 is used in precision instruments, optical systems, and aerospace tooling where temperature stability is critical. Common applications include measurement instruments, optical mounts, composite mould tooling, and bimetallic thermostats. It is also used in electronics, semiconductors, and structural parts that must maintain consistent alignment under temperature changes.
What are the uses of Invar 36 Plate?
Invar 36 plate is used in large, flat precision surfaces such as metrology bases, tooling plates, and optical benches. Its dimensional stability ensures accuracy in high-precision environments.
What are the uses of Invar 36 Round Bar?
Invar 36 round bar is used for rods, shafts, and pins that must remain dimensionally stable under varying temperatures. It is often machined into precision cylindrical parts.
What are the uses of Invar 36 Square Bar?
Invar 36 square bar is used in rigid frames and support structures where flat surfaces and low expansion in multiple directions are required.
What are the uses of Invar 36 Flat Bar?
Invar 36 flat bar is used for mounting rails, supports, and machine components where low thermal growth and a rigid profile are needed.?
What are the uses of Invar 36 Sheet?
Invar 36 sheet is used for thin covers, panels, and structural skins in optical or vacuum systems that must remain dimensionally accurate across a wide surface area.
What are the uses of Invar 36 Coil?
Invar 36 coil, or strip form, is used for automated stamping and forming of small precision components like electrical connectors and spacers.
What are the uses of Invar 36 Wire?
Invar 36 in wire form is used for fine structural supports, tension elements, and sensor leads that require minimal thermal expansion and high stability.
