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Invar 36

Global Supplier of Invar 36

City Special Metals are 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) 1268 774 261, email or alternatively complete the contact form below. 

Invar 36 Stockist Range

Product Form Range From Range To
Invar Plate icon

Invar Plate

4mm 400mm
Invar Round Bar icon

Invar Round Bar

4mm 500mm
Invar Square Bar icon

Invar Square Bar

70mm 400mm
Invar Flat Bar icon

Invar Flat Bar

N/A 250mm x 250mm
Invar Sheet & Coil icon

Invar Sheet & Coil

0.025mm 3.175mm
Invar Wire icon

Invar Wire

0.15mm 3.5mm

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    Beneficial 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

    Markets & Applications

    • Moulds and lay up tools for composites
    • Devices, electrical transformers and circuit breakers
    • Precision equipment elements as such as: lasers, measuring and positioning devices, thermostats, precision condenser blades
    • High voltage transmission lines
    Call City Special Metals +44 1268 774 261

    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%)

    Technical Specifications

    ASTM UNS Werkstoff
    F1684 K93603 1.3912


    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

    Physical Properties

    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 446
    °C 230
    Melting Point °F 2462
    °C 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

    Invar 36 Information

    Invar 36 (FeNi36) is a nickel-iron, low expansion alloy that exhibits a near zero rate of thermal expansion and is able to maintain almost constant dimensions from cryogenic temperatures to 260°C. It has become a popular choice when it comes to composite material manufacturing.

    Call City Special Metals +44 1268 774 261

    We offer a bespoke service so, if you don’t see the size or form that you require, contact us either by phone, email or our contact form below, and we will provide a solution to your requirements.

    A Popular, Low Expansion Alloy

    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 effective bimetals 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.

    If you'd like to know more about Invar 36's history and legendary status, read our blog article: "Invar - A Legend in Metals" which can be found in our insights area.

    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