Induction hardening is widely used in the automotive industry, where it benefits high-performance automotive parts. Induction hardening refers to the enhancement of various physical, mechanical, and chemical properties by localized heating of the material. This heat treatment process utilizes an induction coil, which heats the workpiece employing an electric current, followed by a quick cooling process.

What makes the hardening process so valuable? The intense heating of metal and quenching phenomena alters the quality of the workpiece. It improves wear resistance, fatigue strength, tensile strength, corrosion resistance, hardness, and many other properties. The hardened surface protects the core while being ductile to ease further machining operation.

Induction hardening applies to various industries, including mechanical tools, construction, railway, automotive, agriculture, and many more. However, this article will exclusively discuss automotive applications of induction hardening.

Which Materials are Hardened for Automotive Parts?

Aluminum, steel, copper, titanium, and plastics are the most commonly used materials in the automotive industry. Titanium is employed in high-temperature areas, aluminum offers a high strength-to-weight ratio, and steel is famous for its body structure.

Steel alloys are the most common material hardened for automotive applications. Various vehicle components rely on the induction hardening of steel to meet the required properties. It increases the hardness, strength, impact resistance, and durability. It is recommended to use carbon steel with at least 0.35% carbon in induction hardening for automotive applications.

It might become confusing if you are more familiar with alloy grade than carbon content. Then, the following alloy series can be subjected to induction hardening for automotive applications; 1045, 1050, 1144, 4140, 4150, 4350, 5150, and 8650.

Induction Hardened Automotive Parts

Hardened steel is massively used in the automotive part, from the structural component of a vehicle to interior design. The strength of induction-hardened steel provides functionality for cylinders, crankshafts, axles, camshafts, and gears over an extended time.

Following are the major automotive parts that require an induction hardening process:

Small size Hardened steel is used in the automotive industry to create small parts, such as gears, axles, steering racks, tulips, and wheel hubs.
Large size Large-size automotive parts also rely on induction hardenings, such as shafts, floor, valves, springs, connecting rods, and many more.

Now let’s discuss the various sections of an automobile to know which parts require induction hardening.

Automobile SectionDescription
Engine partsShaft, rocker arm, valves, balancing shaft, and engine block head.
SteeringSteering pinion, pump shaft, pump valves, steering knuckles, and ball joints.
Transmission & DrivelineOutput shaft, fix-outer race, sleeve gear axle shafts, inner race, outer race, and tripod housing.
Brake & suspensionShock absorber rod, springs, hub wheel bearing, torsion bar, anti-roll bar, rear beam, and many more.
OthersOther parts in a vehicle require induction hardening for their functionality. The list of other parts also includes the front & rear body beams, seat components, and the muffler line (exhaust system).

How does Induction Hardening address the Requirement of Automotive Parts?

We already discussed which automotive parts require induction hardening. Now let’s discuss how induction hardening addresses the requirement of automotive parts. High mechanical strength, hardness, impact resistance, wear resistance, corrosion resistance, durability, and dimensional accuracy are critical requirements for automotive parts. Induction hardening addresses all these requirements cost-effectively.

The induction hardening process alters the internal structure of steel and other material so that more and more carbon atoms are adjusted in iron crystals. The restriction of carbon diffusion by a quick quenching process stabilizes the structure changes. These changes in carbon-iron content increase the hardness of automotive parts. Similarly, material grain boundaries are arranged in a way that requires more force to slip, contributing to the high strength of components.

The increase in hardness from induction hardening makes the parts more resistant to wear and tear, scratches, and corrosion. All these properties manipulated by induction hardening make the part suitable for the functionality of various systems, such as engine, driveline, load bearing, braking, and others.

Auto parts

Advantages of Induction Hardening in the Automotive Industry

Induction hardening is the best approach to customizing various physical & mechanical properties required for automotive parts. It is controlled and localizes the heating procedure, which offers complete control over the manufacturer to obtain the properties precisely at the desired level.

It is also a practical approach for mass production, the repeatability, dimensional consistency, and accuracy are exceptional with induction hardening. This technology is not complicated to operate and only requires digital instructions and handling a few parameters, such as current and voltage. Induction hardening has many benefits. The high energy efficiency and automation help to get outstanding results and reduce the overall cost of manufacturing, so why not go with induction hardening?

  • Induction hardening of automotive parts offers complete control over time and temperature.
  • The automation in induction hardening gives excellent repeatability, so it reduces the number of defective parts.
  • Unlike other approaches, such as furnace heating, it does not involve any risk of combustion.
  • Automotive parts with complex geometries can be hardened uniformly using induction hardening.

Conclusion: Strengthening the Automotive Industry with Induction Hardening

The current competitive automotive market is continuously looking for enhancement of various capacities of parts, especially in terms of strength and durability. The induction hardening process addresses the diverse requirements and strengthens the parts. It can provide the required strength and hardness for crankshafts, valves, housing components, suspension parts, steering parts, engine blocks, shafts, and many other automotive parts.

Manufacturing automation and robots are the future of the automotive industry. The sophisticated induction hardening machines can be automated according to requirements and follow future trends.

FOCO induction provides induction hardening solutions for a wide range of industries. Induction heating is the most cost-effective form of industrial heating in modern industry. It has the characteristics of high efficiency, reliability, safety, and trouble-free operation. Best of all, it is easy to integrate into your automated production line. Our professional engineers will assess your individual heating needs and provide you with an induction heating system that meets your specific heating process requirements.


What are the applications of induction hardening in the automotive industry?
Induction hardening is applicable to customize the various properties of shafts, valves, steering parts, axles, connecting rods, bearings, torsion bars, engine blocks, beams, and many more.

How does induction hardening strengthen the automotive industry?
The desired hardness and mechanical strength level can be obtained for various automotive parts. It is an accurate, energy-efficient, cost-effective approach to customizing different properties. Additionally, it is compatible with complex geometry as well.

How can I achieve the best induction hardening results for automotive parts?
The capacity of the induction hardening machine is the primary factor for quality results. Advanced and automated CNC hardening machines can be controlled to get the exact result as desired.