A cartridge heater is a tube-shaped, industrial heating element that can be inserted into drilled holes. Cartridge heaters provide localized and precise heating and are commonly used in the heating process industry.The construction of a cartridge heater begins with a ceramic core with a resistance wire wrapped around it. The core and resistance wire are encased in a dielectric metal sheath made of steel or stainless steel.Cartridge heaters are used as a water heater element and in a wide variety of applications. Some of these uses include bag sealing applications, hydraulic oil applications, motor oil applications, gearboxes, water heating applications as well as laboratory and food equipment.