Specific resistance (at 20° C)

Letters in Gost Stamps and Density of Metals
International steel equivalents
Specific resistance
Substance Specific resistance
μOhm - mm2/m
Aluminum 0,028
Tungsten 0,055
Iron 0,098
Gold 0,023
Constantan 0,44-0,52
Brass 0,025-0,06
Manganine 0,42-0,48
Copper 0,0175
Molybdenum 0,057
Nickelin 0,39-0,45
Nickel 0,100
Tin 0,115
Mercury 0,958
Lead 0,221
Silver 0,016
Tantalum 0,155
Fechral 1,1-1,3
Chromium 0,027
Zinc 0,059
Substance К Substance К
Aluminum 0,0042 Tin 0,0042
Tungsten 0,0048 Platinum 0,004
Constantan 0,2 Mercury 0,0009
Brass 0,001 Lead 0,004
Copper 0,0043 Silver 0,0036
Manganine 0,3 Steel 0,006
Molybdenum 0,0033 Tantalum 0,0031
Nickel 0,005 Chromium 0,006
Nickelin 0,0001 Fechral 0,0002
Nichrome 0,0001 Zinc 0,004

Alloys (composition in %):

  • Constantan (58.8 Cu, 40 Ni, 1.2 Mn)
  • Manganin (85 Cu, 12 Mn, 3 Ni)
  • Neusilber (65 Cu, 20 Zn, 15 Ni)
  • Nickel (54 Cu, 20 Zn, 26 Ni)
  • Nickel (67.5 Ni, 15 Cr, 16 Fe, 1.5 Mn)
  • Reonate (84Cu, 12Mn, 4 Zn)
  • Fechril (80 Fe, 14 Cr, 6 Al)

Nichrome resistivity

Every body through which an electric current passes automatically offers a certain resistance to it. The property of a conductor to resist electric current is commonly referred to as electrical resistance.

Let us consider the electronic theory of this phenomenon. As free electrons move through a conductor, they constantly encounter other electrons and atoms in their path. By interacting with them, the free electron loses some of its charge. Thus, the electrons encounter resistance from the material of the conductor. Each body has its own atomic structure, which offers different resistance to electric current. The unit of resistance is considered to be ohms. The resistance of materials is denoted by R or r.

The lower the resistance of a conductor, the easier it is for an electric current to pass through that body. And vice versa: the higher the resistance, the worse the body conducts electric current.

The resistance of each individual conductor depends on the properties of the material from which it is made. In order to accurately characterize the electrical resistance of a particular material, the concept of specific resistance (nichrome, aluminum , etc.) was introduced. Specific resistance is the resistance of a conductor up to 1 m long, with a cross-section of 1 sq. mm. This value is denoted by the letter p. Each material used in the manufacture of a conductor has its own specific resistance. For example, let us consider the specific resistance of nichrome and fahril (over 3 mm):

  • X15N60 - 1.13 Ohm*mm/m
  • X23Yu5T - 1.39 Ohm*mm/m
  • Х20Н80 - 1.12 Ohm*mm/m
  • CrN70U - 1.30 Ohm*mm/m
  • CrN20US - 1.02 Ohm*mm/m

The specific resistance of nichrome and fecherrals indicates their main scope of application: the manufacture of heat-activated devices, household appliances and electric heating elements of industrial furnaces.

Since nichrome and fecheral are mainly used in the production of heating elements, the most common products are nichrome filament, ribbon, strip X15H60 and X20H80, as well as fecheral wire X23Yu5T.