Why Use Induction for Shrink Fitting?

Induction delivers heat to the targeted part, not the atmosphere around it, so there is no risk of distortion and temperature can be controlled in a precise manner. Safety is improved, since it does not use an open flame.

Can Induction Be Used for Insertion and Disassembly?

With induction shrink fitting, you use thermal expansion to fit or remove parts. A metal component is heated to 150-300 °C (305-572 °F), and that causes it to expand. This allows for the removal or insertion of a part.

What Is Induction Shrink Fitting?

Induction shrink fitting is a process in which a precise electromagnetic field is used to heat and thermally expand an electrically conductive material prior to assembly, resulting in an interference fit joint upon return to ambient temperature.

What Is Induction Shrink Fitting?

What Benefits Does Induction shrink-fitting Offer?

Meets tight production tolerances with precise localized heat to small areas creating pinpoint accuracy
Increases production rates with faster heating cycles
Reduces defect rates with repeatable, reliable heat
Eliminates variability from operator-to-operator, shift-to-shift
Maintains metallurgical characteristics of the individual metals

Shrink Fitting a Steel Part into the Casing

A specially designed multiple turn internal helical coil was used to provide the heat to the various steel parts.

Shrink Fitting Magnetic Steel Pistons

Using induction for shrink-fitting magnetic steel pistons onto a chrome shaft; the client was using an unreliable handheld induction system and wanted a higher quality induction shrink-fitting solution.

Heating Hammer Bits for Shrink Fitting

Shrink-fitting hammer bits with induction for the insertion of carbide buttons; the end product is a drilling tool for the oil and gas industry.

Shrink Fitting a Magnetic Steel Gear

Induction shrink-fitting with EASYHEAT takes 45 minutes to heat the sample to the required temperature. The current oven process takes over two hours.

Shrink Fitting of Bearings

A multi-turn helical coil delivers uniform heat to the entire range of the bearing sizes in the transverse mode.

Shrink Fitting an Aluminum Tube (optical system)

With an EASYHEAT 2 kW induction shrink-fitting system, the aluminum tube heated to the required temperature within 30 seconds. Shrink fitting then took place

Shrink fitting an automotive aluminum motor housing

Induction shrink-fitting is fast, presents significant energy savings over an electric oven, requires a more modest footprint than an oven and can be easily integrated into an automated process

Inserting a Steel Bushing to an Aluminum Hub

The client currently uses an electric oven and the heating time is two hours, so at 60 seconds, the time savings with induction shrink-fitting is very significant

Shrink Fitting A Gear to a Shaft (Automotive)

The customer was using a torch, which can lead to inconsistent part quality. Induction's precise heating means the client can count on consistent results in their process

Shrink Fitting an Aluminum Motor Housing

The customer was using a cold press, but it was creating part defects. This was resolved with induction heating: the process took just two minutes compared to 40 minutes and they were able to achieve their targeted production rate.

More shrink-fitting Application Notes

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Shrink Fitting Stainless-Steel Sleeve & Shaft

The customer currently uses electric ovens that run 24 hours a day, 5 days per week and their primary concern is to save on the energy cost of heating the parts in the ovens.

Shrinkfitting a steel mud pump liner

A twenty-turn helical coil is used to heat the chain. The chain is fed through the coil at a rate of 1 meter per minute to reach the desired 1760 °F (960 °C) for the tempering process...

Shrink fit a steel gear onto a steel gear motor shaft

A four-turn helical internal coil is used to heat the gear bore. The coil is inserted into the gear bore and power is applied for 90 seconds to reach the required 400 °F (204 °C) and expand the gear bore...

shrink-fitting a carbide ring into a valve seat

A three turn helical coil is used to heat the steel valve seat. The steel valve seat is placed in the coil and heated for 50 seconds to enlarge the center hole & drop the carbide ring in for the shrink-fitting process.

Shrink-fitting auto turbo charger impeller blades onto an aluminum shaft

Induction heating provides repeatable results, reduced cycle time, lower consumables cost and even distribution of heating

shrink-fitting aluminum pulley to insert inner bearing

A three turn helical coil is used to heat the aluminum pulley. The pulley is heated to 464 °F (240 °C) in 20 seconds to expand the inner diameter and then the inner bearing is inserted to form the completed part.

shrink-fitting an assembled wrist pin into a connecting rod

Induction heating provides more accurate control of heat vs a flame burner, it heats only the knuckle, not the whole part, it prevents discoloring due to lower temperature used and increases productivity due to repeatability & ease of operation. A foot pedal & timer is used.

shrink-fitting a cast iron rocker arm assemblies

A four-turn helical coil heats the ring at one end of the assembly. The coil is designed to concentrate the field towards the center of the assembly where the thermal mass is greatest.

Shrink fit a motor shaft and roller

Processing with induction heat saves power and time. The complete tube does not have to reach the desired temperature as it does when heating with an oven. Being able to selectively heat a zone allows for a much quicker transfer of heat.

Shrink-fitting a Camshaft Gear

Heating a camshaft gear with a bore size of 1.630 inch to shrink fit over a steel shaft that has a diameter of 1.632 inch. A temperature of 500F is required for the gear to expand 0.002 inch in order to slip over the shaft.

shrink-fitting a Fuel Pump Housing and Inserts

To heat an aluminum fuel pump housing measuring 8 x 45 x 3.5 inch to 375F, allowing steel parts to be inserted.

Shrink Fitting Cam Shaft Gears

To heat aluminum and steel camshaft gears to over 500°F within 4 minutes for a shrink fitting application.

Shrink fit a carbon graphite ring insert into an outer steel band

Induction heating provides a highly effective joint, accurate & repeatable heat, precise control of cycle times, uniform and repeatable results and hands-free heating that involves no operator skill for manufacturing

About Induction Heating

Induction heating is a fast, efficient, precise and repeatable non-contact method for heating metals or other electrically-conductive materials. The material may be a metal such as brass, aluminum, copper or steel or it can be a semiconductor such as silicon carbide, carbon or graphite. To heat non-conductive materials such as plastics or glass, induction is used to heat an electrically-conductive susceptor, typically graphite, which then transfers the heat to the non-conducting material.

Read our 4-page brochure; learn more about how the science of induction technology can solve your precision heating problems.