Common Trade names: Nilo 36, Invar 36, Pernifer 6, Invar 6, Nilo6

Common trade names: Invar 42, Nilo 42


42NiFe is an iron-nickel controlled expansion alloy suitable to glass sealing, with optimal chemical composition to obtain hermetic seals. Typical applications are integrated circuit lead frames, electron gun components, enamelled resistor ferrules and moulds for composite parts.

42NiFe shows almost negligible expansion up to 300°C and possesses large value of magnetic permeability. It is extensively utilized in the aerospace industries and manufacturing thermostat rods.

Chemical composition

Iron FeBal. NickelNi42.0%

Mechanical property

Alloy State Tensile Strength, N/mm² Yield Strength, N/mm² Elongation, %
Wire 490.00 250.00 43.00

Physical properties

Density (g/cm3) Resistivity at 20 oC (μohm.cm) Melting To (oC) Curie To (oC) Specific heat (J/g oC) Termal
conductivity at
20 oC (W/m/oC)
8.15 63.0 1425.0 330.0 0.5 12.5


  • lower thermal expansion
  • good magnetic permeability


  • lead cables
  • electronic operations
  • glass sealing and vacuum equipments