Resistance Wire 101: What It Is, How It’s Used, and Why Engineers Trust MWS
- What is Resistance wire?
- What kinds of resistance wire does MWS Provide?
- Why does quality matter with resistance wire?
- What are the Key Selection Factors for Choosing a Resistance Wire?
- What are the common applications for resistance wire?
- Resistance Wire by the Numbers.
- Where to learn more about MWS Resistance wire.
What is Resistance wire?
Resistance wire is a specialized electrical conductor designed not to maximize conductivity, but to restrict electric current and convert electrical energy into heat. This unique characteristic makes resistance wire fundamental to countless applications ranging from household appliances to sophisticated industrial controls such as sensors, relays and thermocouples. Understanding the science, the applications, and the key selection factors for resistance wire can help engineers and manufacturers choose the perfect wire for their needs.
What kinds of resistance wire does MWS Provide?
MWS provides resistance wires based on Copper-Nickel, Nickel-Chromium, Nickel-Iron and more. These resistance wire alloys are available in annealed or tempered conditions, and can be sold in the following conditions:
- Annealed or tempered per relevant ASTM specifications
- Bare wire or insulated with a variety of different polyester or polyurethane insulations with thermal classes up to 240°C with Polyimide ML
- Resistance wire can also be shaped in different rectangular or flat wire geometries
- Can be plated, bondable, laser ablated, straightened, or cut to discrete lengths either loose or discrete lengths on spools.
Why does quality matter with resistance wire?
While resistance wire is most commonly known just as a heating element for both home and industrial applications, certain alloys of this wire are also used in many precise control systems such as cryogenic sensors, voltage regulators, and critical safety systems such as fire detection systems in aircraft. When using resistance wire in your critical applications, it’s important to know your wire was manufactured correctly. MWS takes quality and cleanliness seriously with resistance wire with full inventories traceable to heat and lot numbers in a clean, ISO certified, and controlled environment.
What are the Key Selection Factors for Choosing a Resistance Wire?
Resistivity
The purpose of resistance wire is to either convert electricity into heat or to control the electrical properties of the wire’s voltage and current. The main physical factors that affect a wire’s resistance value are length, cross sectional area, and the specific resistivity value of the alloy. MWS resistance wire can made to a specific resistance within a ±3% to ±5% tolerance.
Temperature Coefficient of Resistance (TCR)
For applications demanding precision and stability, the TCR of an alloy describes how its resistance changes with temperature. This factor is crucial when the wire must perform consistently under varying thermal loads.
Corrosion and Oxidation Resistance
Many environments are harsh, so corrosion and oxidation resistance are essential for longevity. Alloys with good oxidation resistance prevent oxide buildup – maintaining performance and reliability, especially at high temperatures.
Geometry
The geometry (shape and size) of resistance wire influences its resistance. Both round and shaped wires can be engineered for specific resistance values, and wires can be custom-cut for particular applications.
What are the common applications for resistance wire?
Common resistance wire applications include RTD sensors, cryogenic sensors, thermocouples, rheostats, voltage control relays, as well as heating elements in devices like industrial kilns, hot wire cutting devices, and EDM machining.
Resistance Wire by the Numbers
- Resistivity Range: MWS resistance wire alloys span from as low as 30 OHMS/CMF (Nickel-Copper MWS-30) up to 875 OHMS/CMF with Chromium based alloys (MWS-875) to suit diverse heating and sensing applications.
- Operating Temperatures: Chromium-based alloys like Nichrome (MWS-675) can operate at temperatures up to 2192°F (1200°C), with pure nickel alloys rising to 2600°F (1427°C) for severe environments.
- Wire Size Options: Offered in sizes from 0.064 inches to 0.0006 inches depending on the alloy, MWS provides precision control over resistance and heat in any application.
- Inventory: MWS has over 40,000 square feet of warehouse space, providing thousands of resistance wire products and with expedited shipping as an option.
- Custom Resistance Tolerance: Typical resistance values can be specified within ±3% to ±5% tolerance, meeting exacting requirements for custom applications.
Where to learn more about MWS Resistance wire.
To learn more about how we can provide a perfect solution to your engineering needs contact our sales team or view our resistance wire product page.