Nexthermal Medium Watt Density Cartridge Heaters

Nexthermal’s medium watt density cartridge heaters are a value alternative to a high watt density heater. They are the right choice for high temperature applications that do not require integrated thermocouple, precise wattage distribution, are less than 65 watts per square inch on the heater sheath, and have lengths greater than 7 in.

Don’t let the fact that this is a value line lead you to believe this is of lower quality than that of a high watt density heater. Medium watt cartridge heaters feature a similar construction as low watt density heaters with spiraled resistance wire inside of ceramic. However, unlike low watt heaters you may see in the market place, Nexthermal’s medium watt density heaters swaged, compacting the ceramic and MGO for improved durability and faster response.

Options High Watt Density Med. Watt Density Low Watt Density
Thermocouple J or K Yes No No
Highly Compressed MgO Yes Yes No
Internally Connected Leads Yes Yes Yes
Swaged Leads Yes Yes No
Wattage Distribution Precise Yes No
High Movement Applications Yes Yes No
12v, 24v, 48v Compatible Yes Yes Yes


Nexthermal can help you with your new product development, solving a cartridge heater problem, or just getting you a replacement heater.

New Product Development

For more simple applications that don’t require precise heating wattage distribution, the medium watt density cartridge heater is a durable high value alternative. Built to Nexthermal exacting standards, it is a proven performer.

Solving a Cartridge Heater Problem

Nexthermal can work with you to improve the durability of your medium watt density heater. Do your failed cartridge heaters have similar characteristics? If so they hold clues as to the root cause of failure. Nexthermal can evaluate your failed heater and identify the right configuration to improve durability.

Replacement Heater

Nexthermal medium watt density cartridge heaters allow you to build Nexthermal quality into your equipment without the premium cost.

The Nexthermal cartridge heater configurator puts the engineering tools in your hands to design the correct heater for your application specific needs. This program guides, and informs you on design criteria with an easy to use graphical interface. In less than 2 minutes you can engineer your heater.

Nexthermal Advantage

  • Ships out in 7 business days
  • Imperial and metric sizes available
  • Ideal for heating large amounts of mass at a stabilized temperature
  • Proven durability in impact and vibration environments

Technical Data

  • Heater Sheath: CrNi Steel
  • Insulation Material: Highly Compressed MgO
  • Heating Wire: NiCr 8020
  • Maximum Sheath Temperature: 1382° F
  • High Voltage Stability <= 24v Nominal: 500VAC (cold)
  • High Voltage Stability > 24v Nominal: 1500VAC(cold) *Higher on request
  • Insulation Resistance: min. 5M Ohms @ 500 VDC (cold) >5M Ohms on request
  • Discharge Current: max0.5mA @ 253 VDC(cold)
  • Length Tolerance: +/- 1.5% (min. +/- 1mm) *Others on request
  • Resistance Tolerance: +/- 10% smaller on request
  • Diameter Tolerance Standard: +/- .002 in.
  • Diameter Tolerance Premium: +/- .0008 in.
  • Maximum Voltage: 440V *Consult Engineering for your Diameter Size
  • Maximum Warranted Watt Density: 80 Watts/In2 *With Premium Diameter Tolerance
  • Length of Unheated: Lead End = 5-25mm 4-10mm; Disc End = 54-9mm
  • Maximum Length: 118 in. *Consult Engineering for your Diameter Size
  • Supported Diameters Imperial (in.): ¼, 3/8, ½, 5/8, ¾
  • Supported Diameters Metric (mm): 6.5,  8, 9.5, 10, 12.5, 12.7, 15.8, 16, 19, 20, 22


  • Rubber Molding
  • Food processing equipment
  • Packaging
  • Extrusion
  • Platen heating
  • Immersion heating