• Kristin Thompson

Ask The Expert: Induction Heating



How does induction heating work exactly?

Simple explanation; The Miller Pro Heat 35 Induction system heats metal from the inside out, by generating “eddy” currents throughout the steel. This is done by a process of changing polarity thousands of times per second .

What applications can really benefit from induction heating systems?

  • Preheating of Welds

  • Post-Weld Heat Treatment and Hydrogen Bake-out

  • Coating Removal

  • Shrink fit Application or Removal by expansion

What is the most unique application you have seen an induction heating system used for?

Shrink fitting the rail tire on the axle for the Fort Edmonton Park steam train.

We had to expand the Steel, 4“ thick by 48” diameter tire by 1/8” in Diameter to set the axle in and let cool to have a perfect interference fit.

It saved hours in preheat time compared to the traditional propane "ring of fire" method.


Are there different applications for the air-cooled vs. the liquid-cooled systems?

Pre-heat with the use of air cooled blankets for temperatures up to 400 degrees F, used on pipe from 8.625” to 60” diameter, or flat plate with blanket covering 13.1”W x 40”L to 7.5” W to 197” L

Pre-heat, hydrogen bake-out and post weld heat treatment applications are done with liquid cooled coils, with temperatures up to 1400 degrees F.

Because the liquid cooled coils are flexible, any possible configuration can be designed to cover the dimensions of the steel to be heated. With this processes a Digital recorder can be added for quality control purposes.


We now Have Rolling Induction systems for pre-heating of pipe in spooling applications which works with the water cooled systems.

What are the biggest benefits of utilizing Induction Heating?

  • Safe coils, significantly improving work environment

  • Heating while welding

  • Consistent, continuous heat

  • Quick time-to-Temperature, often minutes vs. hours

  • Performs at full output for a fraction of the cost

  • Induction only heats target metal not work space

Learn more about induction heating here