Electrical Resistance Wire & Tapes - Knight Group

Electrical Resistance Wire & Tapes

Resistance wire is engineered to resist the flow of electricity, expertly converting electrical energy into heat. At Knight Precision Wire, we excel in producing high-quality resistance wire in various configurations, including round wire, tape, ribbon, and strand forms, catering to a wide array of applications.

Electrical Resistance Wire Grades

Alloy 200

Nickel 212

Alloy 600 / INCONEL® 600 / 2.4816 / N06600

Alloy 601 / INCONEL® 601 / 2.4851 / N06601

Ni Cr 37/18 / Ni Cr 3718

Ni Cr 60/16 / NO 6004 / 2.4867 / Ni Cr 6015

Ni Cr 80/20 / NO 6003 / 2.4869 / Ni Cr 8020

Nilo® 42 / K94100 / K94101 / NiFe42

K94610 / Nilo K / 29/18 / NiFeK

Nilo® 48 / K94800 / NiFe48

Nilo® 36 / K93603 / NiFe36

Nilo®52 / N14052 / NiFe52

CuNi6 / 2.0807 / Alloy 60

CuNi2 / 2.0802 / Alloy 30

CuNi44 / Hecnum / 2.0842

CuNi10 / IMPHY® CuNi10 / 2.0811

CuNi23 / IMPHY® CuNi23 / 2.0881

Cr Al 20-5 / 1.4767 / K 92400 / ICA 135

Cr Al 25-5 / 1.4765 / K 92500 / ICA 145

Electrical Resistance Wire

Resistance wire is specifically designed to resist the flow of electricity.  This property allows it to convert electrical energy into heat as the electrical current is passed through it.  Electrical resistance wire is primarily used for industrial and domestic heating elements. However, it has applications across many sectors ranging from automotive, aerospace, electronic, medical and scientific industries.

Through our brand Omega Wire, Knight Precision Wire Ltd excel in producing high-quality resistance wire in a variety of forms and configurations, including round resistance wire, resistance tape, resistance ribbon and resistance strand.  The cornerstone of our resistance wire products is their exceptional ability to perform under extreme temperatures and robust resistance to corrosion. For applications demanding the highest temperature resilience, our nickel alloys—such as nickel chrome, nickel chromium 80/20, and nichrome 60/16—are the materials of choice. For less intensive thermal applications, we offer durable alternatives like copper-nickel, cupro-nickel, nickel-iron, and iron chrome aluminium (ICA).

Resistance Strand​: Standard and Custom configurations

Our resistance wires are manufactured from nickel alloys which have specialist properties such as electrical resistance, oxidation resistance, strength and corrosion resistance – all at elevated temperatures.  We take pride in our capability to produce custom resistance strand configurations tailored to meet specific requirements in resistance or size. Offering standard constructions of 7, 19, 37, and 49 strands in a broad spectrum of alloys, we ensure versatility and precision. For projects necessitating annealed strands, we employ dedicated strand annealing lines for optimal results. With many of our strands readily available from stock and custom configurations orderable upon request, we are dedicated to meeting our clients’ unique needs.

Alloy

Common Name

Standard Strand Construction (mm)Resistance (Ohms/m)

Nickel Chrome 20/20

NiCr 80/20

Nichrome 80/20

19 x 0.5440.233 - 0.269
NiCr 80/20

Nichrome 80/20

19 x 0.61 (KING 0.71)0.205 - 0.250
NiCr 80/20

Nichrome 80/20

19 x 0.523 (KING 0.574)0.276 - 0.306
NiCr 80/20

Nichrome 80/20

37 x 0.381 (KING 0.508)0.248 - 0.302

NiCr 80/20

Nichrome 80/20

49 x 1.00 mm (7 x 7 construction) *

NiCr 80/20

Nichrome 80/20

49 x 0.90 mm (7 x 7 Construction) *

NiCr 80/20

Nichrome 80/20

49 x 0.71 mm (7 x 7 construction) *

NiCr 80/20

Nichrome 80/20

49 x 0.45 mm (7 x 7 construction) *

NiCr 80/20

Nichrome 80/20

49 x 0.27 mm (7 x 7 construction) *

Nickel Chrome 60/16

NiCr 60/16

Nichrome 60/16

19 x 0.5080.286 - 0.318
NiCr 60/16

Nichrome 60/16

19 x 0.523 (KING 0.574)0.276 - 0.304

Nickel Manganese

NiMn2%

Nickel 212

7 x 0.9140.022 - 0.027
NiMn2%

Nickel 212

19 x 0.61 (KING 0.71)0.019 - 0.026

Iron Chrome Aluminium

ICA 135

Kanthal D

nearest equivalent

19 x 0.56 mm (KING 0.600) *

0.272 – 0.301

ICA 135

Kanthal D

nearest equivalent

19 X 0.508mm (KING 0.559) *

0.337 - 0.373

* Non Stock items, made to order.
Other typical alloys are ICA 145* and Nickel 200  
We can also provide stranded wire with bespoke electrical resistance requirements and/or construction types.

Resistance Wire Service Properties and Applications

Nickel Chrome Resistance Wire

TypeResistivity µΩ/cmDensity g/cm³

Coeff. of Linear Exp. µm/m°C

(20-1000°C)

Max. Op. Temp °CService Properties & Applications
80/201088.3517.51150Contains long life additions making it suitable for applications subject to frequent switching and wide temperature fluctuations. Control resistors, high temperature furnaces, soldering irons.
60/161128.1617.51100Balance mainly iron and long life additions. Suitable for less exacting applications. Electric heaters and furnaces.
37/181057.95181050Balance mainly iron. Used in furnaces with atmospheres which may otherwise cause dry corrosion for higher nickel content materials. Electric heaters and furnaces.

Copper Nickel Resistance Wire

TypeResistivity µΩ/cmDensity g/cm³Coeff. of Linear Exp. µm/m°C (20-1000°C)Max. Op. Temp °CService Properties & Applications
CuNi 44498.914400Medium resistivity and low temperature coefficient of resistance make it ideal for resistors. Also thermocouples, heating wires.
CuNi 30378.915.7500High resistance to oxidation and chemical corrosion. Resistors, cables, detectors for fuses.
CuNi 6108.916.2300Characterised by low resistivity, high resistance to oxidation and corrosion. Tube electrical welding fittings, ribbons for bi-metals

Iron Chrome Aluminium Resistance Wire

TypeResistivity µΩ/cmDensity g/cm³Coeff. of Linear Exp. µm/m°C (20-1000°C)Max. Op. Temp °CService Properties & Applications
ICA 1351357.25141300Ferromagnetic alloy should be used in dry environment to avoid corrosion. Can become embrittled at high temperatures. Furnace heating elements.
ICA 1451457.115.11350As for ICA 135, but operates at higher temperatures. Furnace heating elements.

Nickel Iron Resistance Wire

TypeResistivity µΩ/cmDensity g/cm³Coeff. of Linear Exp. µm/m°C (20-1000°C)Max. Op. Temp °CService Properties & Applications
Ni 42638.125.3 - 8.0300A low and constant expansion factor up to 300°C enables use in high temperature thermostats. Glass to metal seals, thermostat rods.
Ni 48418.28.7 - 10.3450Coefficient of expansion approximately equals that of soft glasses of soda lime and lead oxide types. Glass to metal seals.
Ni 52438.2510.1 - 10.7450A controlled expansion alloy particularly suitable for seals with soft glasses. Glass to metal seals.
NiFeCo498.365.3 - 6.2400A very low coefficient of expansion closely matches medium hard boro-silicate glasses. High performance glass to metal seals.

Nickel Alloy Resistance Wire

TypeResistivity µΩ/cmDensity g/cm³Coeff. of Linear Exp. µm/m°C (20-1000°C)Max. Op. Temp °CService Properties & Applications

Nickel 200

9.68.913.3325Commercially pure nickel. Good mechanical and corrosion resistance properties. Components for electrical and chemical industries.

Nickel 212

10.98.8612.9325Increased heat resistance due to addition of manganese. Component in bulbs and electron tubes, lead wires.

Quality you can count on

It is critical that the resistance wires can maintain performance at very high temperatures and that they are resistant to corrosion.  Knight Precision Wire stands as a leading specialist manufacturer of Wire and Cable, committed to delivering excellence.  Our resistance wires are crafted from premium nickel alloys, boasting specialised properties that include superior electrical resistance, oxidation resistance, mechanical strength, and corrosion resistance, even at elevated temperatures. This makes them ideal for a wide range of applications including, but not limited to, resistance heating elements, hot wire cutting, heat sealing, precision resistors, and springs and fastenings for high-tech industries. Furthermore, they are widely utilised as essential components in glass sealing applications.

Comprehensive FAQ Guide Electrical Resistance Wire

Electrical resistance wire is a specialised wire used in a wide range of industries for its resistive properties. It is essential in applications such as heating elements, industrial machinery, and medical devices.

We hope this comprehensive FAQ guide will answer all your questions about electrical resistance wire. If you require further assistance or would like to place an order, you can use our contact form01707 645261 or wire.sales@knight-group.co.uk. 

Electrical resistance wire is a type of wire specifically designed to resist the flow of electricity. This property allows it to generate heat when an electrical current is passed through it. The wire is made from materials with high resistivity, such as Nichrome (a nickel-chromium alloy), ICA 135 and ICA 145 (iron-chromium-aluminum alloys), Copper Nickel alloys, and sometimes pure metals like tungsten and molybdenum. 

It is used in a variety of applications, such as heating elements, resistors, and specialised electrical circuits.

Electrical resistance wire works by resisting the flow of electrical current through it, which in turn generates heat as a byproduct.  When an electric current is applied to resistance wire, the electrons moving through the wire collide with the atomic lattice of the wire material, causing resistance to the flow of electricity. This resistance converts electrical energy into heat energy, a principle known as Joule heating. The amount of heat generated is proportional to the square of the current, the resistance of the wire, and the time for which the current is applied.  This heat can be used in applications such as heating elements.

Common materials used in electrical resistance wire include nichrome, iron chrome aluminium alloys and copper-nickel alloys. These materials are selected for their specific resistive properties and high melting points. 

Stainless steel alloys can also be used for low temperature resistance wire in applications where high strength is required.

Electrical resistance wire has a diverse range of uses, ranging from automotive, aerospace, electronic, medical and scientific industries.  It is commonly used for industrial applications, including heating elements, kilns, cutting, and sealing processes in machinery.  Domestic applications include many common household items such as electric ovens, toasters, floor heating systems and resistors in electronic circuits.  Resistance wire is used a range of Medical and Scientific applications and can be found in surgical tools and equipment, and in scientific laboratories for experimental setups.

Selecting the right resistance wire depends on several factors, including the operating temperature, whether the environment is corrosive or non-corrosive, the required life span, and the electrical properties needed. For high-temperature applications, alloys like ICA135 and ICA 145 may be preferred due to their higher melting points. However, for environments where corrosion is a concern, Nichrome could be a better choice due to its superior corrosion resistance.

To help you decide:

  • Consider factors like resistance value, wire diameter, material properties, and operating temperature when selecting wire.
  • Compare types of resistance wire based on temperature range, resistance stability, and durability.

If you need further assistance, contact our dedicated wire sales team using either our contact form, telephoning 01707 645261 or wire.sales@knight-group.co.uk. 

The resistance of a wire is affected by its length, diameter (or cross-sectional area), material composition, and temperature. Specifically:

  • Length: The longer the wire, the higher its resistance.
  • Diameter/Cross-sectional area: A thinner wire has higher resistance than a thicker wire.
  • Material: Different materials have different resistivities, affecting the wire’s resistance.
  • Temperature: As temperature increases, resistance typically increases for metallic conductors.

In simple terms:

Resistance is directly proportional to wire length : The longer the wire, the higher its resistance.

As the length of the wire increases, the path that electrons must travel becomes longer, resulting in more collisions between electrons and the wire’s atoms. These collisions increase the resistance of the wire. Assuming the resistivity and cross-sectional area remain constant, as the length of the wire increases, the resistance also increases. For example, a longer wire will have more resistance than a shorter wire with the same material and cross-sectional area. It is important to consider the length of the wire when designing electrical circuits to ensure proper current flow and efficient operation.

In simple terms:

Resistance is inversely proportional to a wire’s cross-sectional area

According to Ohm’s law, resistance (R) is inversely proportional to the cross-sectional area (A) of the wire. The cross sectional area of wire directly impacts the flow of electrons through the wire.  A larger cross-sectional area provides more room for electrons to move, reducing the likelihood of collisions with the atoms of the wire material. Consequently, a wire with a larger cross-sectional area allows for easier and smoother electron flow, resulting in lower resistance.  Therefore, as the cross-sectional area of a wire increases, its resistance decreases, assuming the length and material of the wire remain constant.

Example: Two wires A and B are made of the same material with equal lengths. Wire A has a larger cross-sectional area than wire B. Due to its larger area, wire A will have lower resistance compared to wire B.

It is essential to understand the relationship between cross-sectional area and resistance when designing electrical circuits. Using wires with an appropriate cross-sectional area helps to minimise resistance, optimise current flow, and ensure efficient operation.

Yes, resistance wire is commonly used in temperature control applications. Its resistance changes with temperature, a property that can be used to monitor and regulate temperature. In some applications, a feedback loop is used with a temperature sensor to adjust the current through the wire, maintaining a desired temperature.

The power output (in watts) can be calculated using Ohm’s Law and the power formula: Power (P) = Voltage (V)² / Resistance (R)

Alternative formulas: P = I²R or P = V²/R

I is the current in amperes
R is the resistance in ohms

This calculation helps in designing heating elements to ensure they produce the required amount of heat.

To calculate the length of wire needed to achieve a specific resistance, you can use the formula:

is the length of the wire
is the desired resistance
is the cross-sectional area of the wire
is the resistivity of the wire material.

It’s crucial to use consistent units (e.g., ohms for resistance, meters for length, square meters for area, and ohm-meters for resistivity) and to know the resistivity of the wire material.

The resistance of a wire can be calculated using the
formula: Resistance (R) = ρ x ( L / A )
where ρ is the resistivity of the material, L is the length of the wire, and A is the cross-sectional area of the wire.

R is the resistance in Ω;
ρ is the resistivity of material in Ω × m;
L is the length of the wire; and
A is the cross-sectional area of the wire.

Maintenance requirements for resistance wire depend on its application and operating environment. Regular inspections for physical damage, corrosion, and degradation of insulation (if applicable) are recommended. In some cases, cleaning to remove any accumulated dust or debris may be necessary, especially in environments where contaminants could affect the wire’s performance or lead to premature failure.

Signs of failure in resistance wire include physical damage such as cracks, breaks, or significant thinning; a reduction in heating efficiency; discolouration beyond normal oxidation; and in some cases, electrical shorts or open circuits. Regular monitoring and maintenance can help identify these issues early, preventing potential safety hazards or equipment downtime.

Yes, resistance wire can be cut to the desired length, joined or extended. However, it requires careful consideration and it is important to maintain the integrity of the wire to ensure a reliable and safe connection for proper functioning. Methods for joining resistance wire include soldering (for some alloys), welding, and using specialised connectors or splices designed for high temperatures. The chosen method should maintain the integrity of the wire’s resistance characteristics and withstand the operating temperatures.

When using resistance wire, it is important to ensure that the wire is properly insulated and mounted to prevent any accidental contact, which could lead to burns or electrical shocks. Additionally, the wire should not be overloaded beyond its maximum temperature and power ratings to avoid damage or fire hazards. Always follow safety standards and regulations applicable to your specific application.

Disposal of resistance wire should follow local environmental regulations and safety guidelines. Since resistance wire can contain metals such as nickel and chromium, it should not be disposed of with common refuse. Recycling is the preferred method of disposal, and many metal recycling centres accept resistance wire. Always check with local waste management services for proper disposal methods to ensure environmental compliance.

You can purchase high-quality electrical resistance wire from Knight Precision Wire. Knight Precision Wire, a division of the Knight Group, is a specialist manufacturer of wire and cable. We offer free quotations on your requirements and can provide expert advice on selecting the right resistance wire for your application.

Knight Precision Wire are specialist wire and cable manufacturers and can provide free quotations on your requirements. You can use our contact form01707 645261 or wire.sales@knight-group.co.uk.

All data is provided for informational purposes only. In no event will the Knight Group and its subsidiaries, be liable for in respect of any action taken by any third party arising from using the information taken from our online or printed sources. Chemical and Mechanical Properties should not be construed as maximum or minimum values for specifications, nor should information be used to assess suitability for a particular use or application. The information and data provided is deemed to be accurate to the best of our knowledge and may be revised anytime without notice and assume no duty to update