Megawatt Heating Elements high watts density cartridge heaters are made of a compacted magnesium oxide, with the resistance wire wound closely to the inner surface to ensure direct heat to the metal surface, and centre-less ground for precision heating. Perfect for the die heating in injection molding tools and extruder heads. Cartridge heaters are used in a wide range of applications ie: water heating, oil, air, and commonly used in the packaging industry. We have a large range of stock of cartridge heaters available and can make to order to suit your application.