Induction Heating Tools

Extinguish the Flame

How to Properly Use and Maintain Induction Heating Coils

Friday October 9, 2020

The induction heating coils that transfer heat from our Mini-Ductor® tools to the objects being heated are a critical element to the process of releasing rusted or seized hardware from corrosion and thread lock compounds. 

Because the coils are a fundamental piece of the induction puzzle, proper care of them is very important.

Here is an overview of these essential accessories, along with some tips for how to properly use and maintain them for the best results.

Don’t want to read all of this? Watch the video!

Coil Styles and Sizes


We carry over two dozen different sized coils to meet various needs. Most of our coils are pre-formed, which means they have been molded into a specific size and shape and will continue to hold that shape throughout the life of the coil. However, these coils can be separated to fit over an inline application and the leads can be bent to fit into hard-to-reach areas without compromising the integrity of the coil.

Bearing Buddy, the Flexible Coil

We also sell flexible coils such as the Bearing Buddy. Though the bearing cannot hold a different shape, it works just as efficiently as one of our pre-formed coils. The bearing buddy kit comes with a heat resistant mat and can be easily wrapped around inline applications. We recommend wrapping the mat around the application before wrapping the coil because the mat extends the life of the coil by protecting the insulation against fraying or abrasion caused by contact with hot metal. For best results, wrap the wire around the application 3-4 times to get the magnetic field going. The more wraps, the better results you will see. 

U-Form Coil

Lastly, we have the U-form coil, which can be shaped or formed into any size you need. Simply take a socket the size of the bolt you want to remove and wrap the U-form coil around the socket to create the perfect-size coil for the job. Again, 3-4 times is the optimal number of wraps to make around the application.

Proper Coil Usage

The first step in proper coil usage is to find the right-size coil to fit your application. The coil should fit around the application with enough space to leave a small gap between the coil and the application.

Second, the coil needs to be secured into place using the coil twist lock from the Mini-Ductor Venom® and Venom HP or the thumb screws if you’re using the Mini-Ductor II.

Next, apply heat for 5-20 seconds to see if you have loosened the application. If not, repeat the process until you can loosen it. These short duty cycles will prolong the life of the unit and the coils. In most cases, there is no need to heat the application to red-hot as we do in our videos and live demonstrations. We do that to demonstrate the safe, precise, and reliable heat our products generate and the speed at which ferrous metals heat up with our tools, but it’s unnecessary for most applications.

How to Recognize Signs of Normal Wear and Tear vs. Damage

After the first use, you may notice that the insulation of the coil will start to brown or darken. This is completely normal and happens over the life of the coil. With proper usage, a coil should last between 200-300 uses. Coils with damaged, frayed, or missing insulation run the risk of arcing and burning the unit out. Arcing can cause the unit to spark, which can be a fire hazard.

Replacement Coils

We do not sell replacement insulation for the coils, but you can purchase replacement coils individually or in one of our many coil kits. All purchases can be made through your local tool distributor or by visiting our website.

Coil Kits

Thin Wall Coil Pack

Bearing Buddy Coil Pack

Standard Coil Kit

Essential Coil Kit

Long Coil Kit

Coil Variety Pack

If you have any questions about proper coil usage or a specific application please email us at

Contact us to learn more about how induction heat can save you time and money.

Induction Innovations, Inc.

U.S. patents: 6670590 and 6563096 apply to all products; D707,804 and D728,086 apply to handheld, inline induction heaters; patent pending for the Mini-Ductor 12V (MD-500)
European Patent Office (EPO): patent 002076372-0001 applies to all handheld, inline induction heaters; patent pending for the Mini-Ductor 220V (MD-800) and Mini-Ductor 12V (MD-500)
Australia patent: 343968 applies to all handheld, inline induction heaters

Induction Innovations has been issued a CAGE code and is SAM registered compliant to do business with the Federal Government.