Induction heating has become prevalent over the past few years. The technology has been used in a variety of industrial applications, such as bolt heating. You may be aware of its uses in induction melting, tempering, hardening, and brazing. Nevertheless, bolt expansion in turbines is another use of induction heating. An induction bolt heater is a machine that helps with it.

Let’s learn more about an induction bolt heater and its advantages.

What is an Induction Bolt Heater?

An induction bolt heater is a revolutionary industrial tool that helps tighten and loosen the turbine and compressor bolts.

It is highly safe in comparison to conventional methods. Moreover, it saves time and labor.

An induction bolt heater delivers precise, rapid, and localized heat. It features a coil that is inserted into the bolt.

The heater generates defined heat that causes the bolt to expand by a certain length. It makes it easier for an operator to remove or tighten the nut bolt.

What is the Process for Induction Bolt Heating?

There are many misconceptions about induction bolt heating. Some people think that it involves the use of sound waves.

The reality is that an induction bolt heater does not operate the way gas and electric heating equipment do.

An induction bolt heater generates heat using induction heating technology. It comprises an induction power supply, which converts line power to an AC (alternative current).

The current helps the heater’s coil to produce electromagnetic fields. These fields then generate a heating effect.

The heat releases the linkage without damaging any surrounding sensitive parts.

When you insert the induction coil into the bolt’s bore, the alternating magnetic field produces electricity in the bolt’s surroundings.

It disperses the induced energy in the form of heat. The induction bolt heater produces non-contact heating.

You need a water-cooling system to cool down the coil and induction system.

Some modern induction bolt heaters come as an all-in-one unit with built-in cooling systems.

What Does an Induction Bolt Heating Machine Consist of?

There are several types of induction bolt heating machines available in the market. Depending on their types and sizes, their making process might be different.

A tie-rod bolt heating machine consists of a central unit attached to the head. The head further had an inductor. The shape of the inductor could be annular or linear.

The heating machine features a user-friendly control panel, an ignition panel, and an emergency button. The control panel features a color display making it easy to use.

Some induction heating machines also have a built-in cooling system.

induction heater front
induction heater front

Advantages of an Induction Bolt Heater

The technology of induction bolt heating has been applied in several fields. Engineers use them at power stations, gas processing plants, chemical plants, oil processing plants, turbines, and more.

Some significant factors that contribute to the popularity of induction bolt heaters are as per below.

Precise Heating

An induction bolt heater delivers precise heating. It generates localized heat. Therefore, you heat the component you want to.

With induction bolt heating technology, there is no guesswork. You get the exact bolt loads.

Since the heating is precise, bolt threads with nuts remain cold during the heating process. It happens because the heating process is so quick that it does not get enough time to penetrate the thread area.

Therefore, it avoids metallurgical damage that is responsible for reducing the lifespan of the bolt.

Depending on your requirement, you can repeat the heating cycle. An induction bolt heater lets you repeat the pre-set temperature and heat pattern.

Safe to Use

Induction bolt heating is several times safer than conventional heating and resistance methods.

This type of heating does not expose people to the risk of burns and other threats. It prevents operators from touching the hot parts.

Since heating coils are continuously cooled with water, it reduces the risk of burn damage.

The induction bolt heater produces non-contact electromagnetic induction heating. The tie rod only has a few hot spots, which makes it easier to tighten and loosen bolts.

Improves Productivity of Operators

Unlike resistance heating and flame, induction bolt heating is time and labor-saving. With traditional methods, it could be a time taking process to tighten or release bolts and nuts in high-pressure turbines.

An induction bolt heater supports quick-release coils. You can attach coils of different shapes and sizes according to your needs.

An operator can lose or tight bolts within 5 to 7 minutes. On the other hand, conventional methods might take up to half an hour.

No Gas and Pollution

Another primary benefit of induction bolt heating technology is that it does not cause smoke or gas.

The induction bolt heating process is clean. It does not involve the use of an open flame.

An induction bolt heater also takes up much space, like a furnace.


The induction bolt heater is user-friendly. An operator with a little bit of training can use it.

Depending on the model of an induction bolt heater, an operator can operate it automatically or manually.

An operator can fit flexible heating heads and cables to the heater according to the project’s demand.

Some heater models also feature an operation failure alarm that detects potential threats and operation failure.


Induction bolt heaters come with several features. For example, you can adjust their power and attach induction heating heads.

Nowadays, induction heating machines are available at different frequencies. These include high-frequency induction heating machines, medium-frequency heating machines, and ultra-high-frequency induction heating machines.

You can choose them as per your project’s demand.


An induction bolt heater is a powerful tool for bolt expansion in turbines. You can use them in chemical plants, power plants, and other industrial settings.

It is a safe alternative to traditional bolt-tightening methods that often have a risk of burning.

It is a fast and accurate technology that offers precise, non-contact heating. If you want to save time, labor, and money, buy a quality induction bolt heating machine. It will increase your productivity during the bolt expansion.