Can Nambu Ironware (Tetsubin) be used with induction heating?

"Can Nambu Ironware be used in induction heating coker?"

"I can’t buy Nambu Ironware since I use induction cooktop burner"

We’ve received such inquiries quite often. In fact, Nambu Ironware works well on induction heating, although it isn’t widely known yet. Therefore, with the characteristics of induction heating in mind, I would like to introduce the advantages and precautions of using Nambu ironware with it.

Nambu Ironware and Induction Heating is the best combination

Nambu Ironware is a representative of traditional craft in Iwate prefecture. Mizusawa-Nambu ironware has a long history that goes back to 900 years. Because of its long history and image as a craft, many people regard it can be used only with direct fire such as gas. However, it actually goes well with induction heating. Then let’s look at the mechanism and characteristics of induction heating first, so that we can see more how it matches with Nambu ironware.

Mechanism for heating cooking utensil itself

How Nambu ironware (Tetsubin) is heated by Induction Heating system

The most distinctive feature of an induction cooker is that it generates heat from cooking utensils such as pots and iron kettles. Once the induction cooker is switched on, the internal coil generates magnetic field lines. When a cooking utensil be closed to the induction cooker, an eddy current is generated on the surface and Joule heat is occurred by the electrical resistance of the cooking utensil. Then the cooking utensil itself generates heat, that is the mechanism of the Induction Heating system.

Simply put, it is a cooking utensil using"Generating heat when electricity is applied to metal.

Other than that, there are also features of high thermal efficiency and reducing the risk of fire as no usage of direct fire like a gas stove.

The requirement of Cooking appliance for Induction Heating

Even though Induction Heating is heat efficient and has low risk of fire, it doesn't mean all cookware can be used. Some materials do not generate heat. In particular, they are cooking utensils made of clay pots, copper and aluminum.

Following three conditions are required to support Induction Heating cookers.

  • A material made to which magnets attach
  • The bottom diameter is greater than or equal to the minimum size specified by the manufacturer of the Induction Heating cooker
  • The bottom adheres with the Induction Heating cooker

As we have seen in the mechanism of Induction Heating, since Induction Heating uses magnetic field lines, the vortex current caused by magnetism does not occur well in materials such as aluminum, copper, and clay pots, which do not have magnets attached.

Also, even if the material is magnetic, the sensor may not respond if the base is too small.

Bottom shape where Induction Heating is not available

Furthermore, even if the size of the bottom is sufficient, it is unable to be used if the Induction Heating cooker does not adhere to the bottom due to protrusions or dents.

Nambu Ironware made of the material which can be used in  Induction Heating

The main raw material of Nambu ironware is cast iron, which contains carbon and silicon.Iron is a  to which magnets attach, and a metal with sufficient electrical resistance to produce Joule heat. As seen in the above Induction Heating system, you can see that these characteristics meet the requirements for cookwares that can be used with Induction Heating.

Another 2 points: "the bottom size" and "unevenness of the bottom".Since each Induction Heating cooker has different specifications, I would recommend checking the specifications such as size and unevenness on the Internet based on the product name and model number.

Use Induction Heating plate for insufficient of the minimum size of the bottom surface.

If the diameter of the bottom surface does not fit and it causes a difficulty for heating, use an Induction Heating plate. An Induction Heating plate is a metal adapter that indirectly heats cooking utensils made of non-magnetic materials, such as aluminum, or small bottom-mounted utensils, such as Macchinetta (a stove-top espresso maker). Please remark that this is not an "Induction Heating mat" for stain prevention of the top plate.

Advantage of using Nambu Ironware on Induction Heating cooker

Boiling water with Nambu ironware gives it a mild taste and is said to boost your iron intake. This is also true when using Induction Heating as a heat source. This time, I would like to look at the advantages of the combination of Induction Heating cooker and Nambu ironware.

Advantage 1 Handle does not get hot 

As Nambu ironware is made entirely of iron, its handle (crane) becomes hot when it is put on fire. Therefore, if you hold it with your bare hand to pour hot water, you are in danger of getting burned. To use it safely, you need a potholder or kitchen mittens.

On the other hand, if you heat it with an induction cooker, the handle won't get as hot as it does on a direct flame. Of course, you still should be careful not to burn yourself, but it's easier to handle than boiling water on a gas stove.

Advantage 2 Rarely change of bottom color

In recent years, it is getting popular of Nambu ironware with variety colors, especially in Europe.One of the advantages of using Induction Heating is that the color of the skin (outer surface) does not change easily.In the case use it with gas stove, the part that directly hits the fire from the bottom to the side will gradually be discolored by the flame. To avoid such color changes, you need to adjust the heating power so that the fire is not larger than the bottom.

On the other hand, in case of using it with an Induction Heating cooker, since you don’t need to use a fire, you can avoid discoloration by fire.I can say, one of the pleasures of using Nambu ironware is that you can see changes one's skin expression the more one uses it, however, I would recommend using an induction cooker for those want to retain the original color as much as possible.


Precautions when using Nambu ironware in Induction Heating

There are many advantages of using Nambu ironware with an Induction Heating cooker, but there are still some points to be careful about. 

The heat is less than medium heat, as there is a risk of deformation

The maximum heat of the 200 V Induction Heating cooker is very strong. Because the temperature changes only at the bottom in a short time, the difference in the coefficient of thermal expansion may cause deformation or damage. As a warning * 4 issued by the Consumer Center, this deformation and damage can occur not only in Nambu ironware but also in all cookware, including stainless steel and other materials. For this reason, it is recommended to use the product at a heat of "medium" or lower.

Products which inside is enameled should be for teapots

The type of product which inside has the smooth glass enamel is not an "iron kettle" that can be used as a kettle, but a "teapot" for making tea by mixing tea leaves and hot water. If you use this for boiling water, the coating of enamel may come off. It is not limited to Induction Heating, the same thing could happen with direct fire such as gas, however Induction Heating cookers require special caution as its wide temperature change.

I’m digressing from Induction Heating, but these teapot type of products with enamel finish inside are coated enamel finish with glass on the surface, so they do not rust and are easy to handle, but it cannot be expected to supply iron.

If you want Nambu ironware for the purpose of boiling water or supplying iron, I would recommend checking if it has an enamel coating inside when you purchase it.



Nambu ironware is originally a product that goes well with Induction Heating. I would be very happy if it would be a chance for people who have thought that they couldn't use traditional craft because their kitchen was induction heating start to use them.

If you use Nambu ironware in an induction cooker, the handle won't be too hot to hold, like when you heat it on a gas stove. In addition, it is easy to prevent huge changes in the color of the bottom, has good thermal efficiency, and is useful for saving electricity due to the cooling loss effect.

Why don't you introduce Nambu ironware into your life that can also be used as an induction Heating cooker? At Nambu Tekki studio OITOMI, you can purchase Induction Heating compatible Nambu Tekki from the online shop at the following link.