Everything You Want to Know About Cartridge Heaters

Everything You Want to Know About Cartridge Heaters

Heating is one of the key processes used in manufacturing units across industries. This is accomplished using various types of industrial heaters, which differ from each other in terms of designs, watt densities, and effectiveness. Cartridge heaters are one of those industrial heaters, which are widely used across industries for heating metals, plastic, and also in immersion applications. These heaters have gained immense traction over the years, and are nowadays preferred over several traditional industrial heaters. This post introduces you to these industrial heaters, their working, applications, and everything you want to know about them.

A Brief Overview of Cartridge Heaters

Cartridge heaters stand out owing to their tube-shaped construction, which also makes them versatile heating elements. These heaters are directly inserted into drilled holes for heating parts made of metal. Like other industrial heaters, cartridge heaters can be designed in different watt densities depending on the application requirements. Typically, these heaters are designed to be slightly undersized than their nominal diameter.

Cartridge Heaters – How Do They Work

The heater consists of a resistance coil that is wound around a dielectric ceramic core. This structure is further encased in a metal sheet. These heaters are driven by AC current. When the current passes through the heater, the resistance coil gets heated and it transfers the heat energy to the metal sheath and then to the surrounding area. This heat energy transfer is known as conduction. As the entire heat generated in the coil is transferred to the surroundings, it is known as one of the effective industrial heaters.

Get Introduced to FIREROD Cartridge Heaters

Did you know cartridge heaters were introduced in 1954 by Watlow under the brand name FIREROD and the heater is popular since then! FIREROD cartridge heaters have been widely favored for the following reasons:

  1. The heaters are fitted with a nickel-chromium resistance wire, which ensures localized heating and even heat distribution.
  2. They possess magnesium chloride (Magnesium Oxide) insulation of specific purity that ensures excellent dielectric strength as well as quick heating.
  3. The outer metal sheath is created by Inconel Alloy 800 that provides resistance from heat and oxidation.
  4. The design is created such that there is minimal space between the sheath and element wire. This results in low internal temperatures.

5 Reasons Why Cartridge Heaters Are Preferred Over Other Industrial Heaters

Owing to their widespread use, today, it is easy to find them across different brands. Although each brand has developed its specifics, these heaters have gained popularity owing to some of their general features:

  1. Compact Construction: These industrial heaters have a swaged construction that compacts the Magnesium Oxide to form a dense dielectric with excellent heat transfer characteristics (changed to correct). The swaged design helps reduce vibration and shocks (Omit). Also, the compact design makes it easy to slip into closed structures such as injection molds as well as die blocks.
  2. Suited for Wide Range of Temperature Applications: Cartridge heaters are suited for a wide range of temperature applications! For instance, they are used for regulating air temperature in various devices, which are exposed to the risk of condensation. Also, these heaters can withstand heating temperatures up to 1400°F.
  3. Effective Energy Transfer: One of the key benefits of using these heaters is that they can transfer heat effectively without losing much heat in the transmission. The metallic sheet around the heater element helps avoid oxidation. The direct contact with the element to be heated further ensures complete heat transfer.
  4. Reduced Electricity Bills: Minimized heat loss lead to low electricity bills. This can help users make huge savings.
  5. Customizable Designs: Although most industrial heaters are customizable, they all have certain limitations due to their designs. However, cartridge heaters possess versatile designs, which makes them highly customizable. The heaters can be designed with built-in temperature sensing capabilities to improve their lifespan. These sensors help prevent overheating that happens in these heaters. Similarly, if used for high-temperature applications, these heaters can be coated with graphite; Teflon lead wires can be used in heaters in applications where they may be exposed to contamination and moisture.

Applications That Use Cartridge Heaters

These heaters are used to heat metal molds, platens, dies, and various metal parts in the metalworking industry. Is that all? No. The following applications also make use of these cartridge heaters.


As the working and benefits of cartridge heaters are well introduced here, you must source them from trusted manufacturers or suppliers. Therm-x is one of the leading suppliers of FIREROD cartridge heaters and other branded heaters in California and west coast region.


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