Electric cartridge heater

Find everything you need to know about cartridge heaters


One of the crucial processes used in manufacturing across many different industries is heating. Electric industrial heaters, which differ from each other in terms of watt densities, design, and temperature ranges are used to accomplish this. Electric cartridge heaters are a type of industrial heater that is used in a variety of industries, including metals, plastics, and packaging, as well as immersion heating applications. Over the years, these heaters have gained large importance and are now preferred for industrial heating processes. This blog gives you an introduction to cartridge heaters, how they work, applications, features, and everything else you need to know.

What are cartridge heaters? 

Electric cartridge heaters, also known as cartridge heaters, are cylindrical heating elements with a heating element wound around a ceramic core. These heaters offer a suitable and reliable way to apply concentrated heat at high temperatures, especially when compact, insert-type heating is needed. Cartridge heaters are renowned for their long lifespan and trouble-free operation. Heating elements are placed in contact with the material being heated for maximum heat transfer. Swaged construction minimizes air gaps, improving efficiency as well as heat transfer. Low, medium, and high watt densities are all compatible in cartridge heaters. They are designed to stand up to a working temperature of 700 °C.

It’s also essential to keep in mind that lots of factors, including the watt density and power rating of the cartridge heater, can affect both the material’s monitored temperature and the actual temperature of an industrial heater during heating operations. The use of stainless steel and Incoloy sheaths provides non-oxidising surfaces.
Furthermore, there are multiple digital temperature controllers available as well; thermocouple and RTDs are the most popular ones that can be placed between the heater and the material’s surface for sensing the temperature.

These miniature cartridge heaters are extremely dependable and effective heaters that allow precise and controlled heating to satisfy a range of manufacturing needs. For more than ten years, Marathon Heaters has been supplying electric cartridge heaters to customers worldwide. We can also offer custom-designed cartridge heaters with the required voltage and watt density, depending on the different industrial applications.


Cartridge heaters, like other industrial heaters, can be designed in different watt densities and temperature sensors according to the requirements of the application. These heaters are typically designed to be slightly smaller than their nominal diameter, which facilitates installation and removal of miniature cartridge heaters.

  1. High-temperature lead wires made of fiberglass or silicon rubber that can withstand temperatures up to 550°C for the flow of current.
  2. Nickel-chromium heating element, evenly wound over a ceramic core for heat transfer.
  3. Ceramic cap with epoxy or cement seal to prevent contamination and to outstand high-vibrations.
  4. Insulation is provided by highly compacted magnesium oxide, which ensures excellent dielectric strength as well as thermal conductivity.
  5. Outer metal sheath made by stainless steel or Inconel sheath that provides resistance to heat and oxidation environments.
  6. End seal to prevent contamination as well as moisture formation.

We can make cartridge heaters as small as 3mm in diameter and 25.4mm in length, with customizable voltage as well as wattage based on requirements.

Working of electric cartridge heater

These heater works on the principle of conduction mode of heat transfer. They consist of a ceramic core which has heating element wound over it as well as compacted MgO surrounded to it which provides dielectric strength, and this structure is further encased in a metal sheet. The insulation in the heater ensures that the heating element never makes contact with the sheath and prevents the sheath from melting in case of any failure. These heaters are driven by AC or DC current. Two- or three-phase voltage is applied via lead wires for the flow of current through the coil. When the current passes through the lead wires, the heating element gets heated; furthermore, it transfers the heat energy to the metal sheath and then to the surrounding area.

What are the benefits of electric cartridge heater?

Miniature cartridge heaters stand out because of their compact as well as tube-shaped construction, which also makes them effective industrial heaters. Due to their wide range of applications, these heaters are used across many industries owing to some of their features mentioned below:

  1. Higher watt density and distributed wattage.
  2. Compact Design: These industrial heaters have a swaged and compact construction that improves dielectric strength with excellent heat transfer properties. Swaged design also helps to reduce vibration as well as shocks.
  3. Suited for a Wide Range of Temperature Applications: These heaters can withstand heating temperatures up to 1400°F.
  4. Sensing of temperature: The heaters can be designed with built-in temperature sensors to improve their lifespan as well as their performance. Furthermore, these sensors aid in the prevention of overheating that occurs in these heaters.
  5. Effective Energy Transfer: The direct contact with the apparatus to be heated ensures maximum heat transfer. Additionally, there is less energy loss, which enhances the effectiveness of the heating process.
  6. Customizable Designs: Because of their adaptable designs, cartridge heaters can be customized according to customer’s need. Download our datasheet for more information on customizable designs of our electric cartridge heaters.


Electric cartridge heaters are most commonly used to heat metal parts by inserting them into drilled holes. They can also be used in liquid immersion heating applications. Cartridge heaters are largely used in the plastics industry for packaging and many other applications. Learn more about how the cartridge heater functions in the plastic packaging industry by watching the video.

Below are some defined applications of cartridge heaters:

  • Die Casting
  • Moulding process
  • Medical Equipment
  • Food and beverage industry
  • Plastic welding
  • Extrusion process
  • 3D printing
  • Semiconductor wafer processing
  • Scientific equipment
  • Plastic packaging process


Marathon Heater is one of the leading manufacturer as well as supplier of electric cartridge heaters and other industrial heaters. We supply a wide range of customizable cartridge heaters with high watt densities. We can also meet demands for non-standard and customized designs. Furthermore, temperature sensors and thermocouples can also be integrated with cartridge heaters. If you require any of our products, please feel free to contact our team by email at