Induction Hardening

Induction Hardening

What is induction hardening?

Hardening is any metallurgical process by which a material is given a higher resistance to plastic deformation. This is accomplished by many methods, including heating. Induction heating has been widely used for decades for this purpose.

Induction generates an electromagnetic field in a work coil that induces currents in the conductive material of a workpiece placed within or near the coil. Friction from these currents elevates the temperature of the workpiece to be hardened. 

Benefits of Using Induction Heating  for Hardening 

Induction heating uses a precise electromagnetic field to raise and hold the temperature of your material to the required level for your hardening process.  This can help you meet tight production tolerances with precise, repeatable localized hardening for faster heating cycles without having to rely on open flame or the restrictions of batch processes.

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Select from our collection of hardening notes, taken from years supporting our customers. Read how we helped to solve their process heating challenges.

image: Hardening surgical blades Hardening surgical blades

To quickly heat a steel surgical blade to 2000°F (1093°C) within 2 seconds so as to harden the blade edge.

image: Hardening Seat Belt PartsHardening Seat Belt Parts

A four-turn helical concentrating coil is specially designed to deliver uniform heat to the steel seat belt retraction gear.

image: Hardening the teeth of a large saw bladeHardening the teeth of a large saw blade

A torch isn't as precise as induction nor is it repeatable; induction heating is highly repeatable, uses less energy than a torch and offers instant on/off heating

image: Case hardening a steel fitting (machined parts manufacturer)Case hardening a steel fitting (machined parts manufacturer)

The coil design enabled the part to be raised into the heating coilfrom the bottom. The design was also made to ensure it will work well within the customer's current setup...

image: Surface hardening of steel screwsSurface hardening of steel screws

Induction heating enables precise application of heat, faster process time and production rates and the ability to be incorporated into existing production lines

image: Hardening teeth on a steel motorcycle gearHardening teeth on a steel motorcycle gear

A single turn helical coil is used to heat the gear. The gear is placed on a spindle and rotated at 300-350 RPM's.

image: Hardening steel screw threadsHardening steel screw threads

A five turn helical coil is used heat the screw threads. The screw is placed in the coil, heat is applied for 8 seconds to achieve a 2 long zone at the required hardness.

image: Hardening the end of steel hand-held marking stampsHardening the end of steel hand-held marking stamps

To harden various size ends of hand held marking stamps. The area to be hardened is 3/4 (19mm) up the shank.

image: Hardening of Steel Cam AssemblyHardening of Steel Cam Assembly

Hardening the cam outer surfaces with induction results in uniform heating for uniform results, one coil can be used for many geometries, consistent results from piece to piece

image: Case Hardening of Armature ShaftCase Hardening of Armature Shaft

A five turn helical coil is used to heat the gear end of the shaft to 1700°F

image: Hardening Cast Iron PulleysHardening Cast Iron Pulleys

Heat cast iron pulleys to 1600°F(871.1°C) in order to achieve a hardness of 55 Rockwell C.

image: Hardening Stainless Steel Surgical Knife BladesHardening Stainless Steel Surgical Knife Blades

A two turn helical coil with an internal quartz tube designed to scan the length of the blade is used to heat the blade to 1850°F (1010°C) to achieve the desired hardness.

image: Hardening Bed Knife Blade for Reel Type Lawn MowersHardening Bed Knife Blade for Reel Type Lawn Mowers

The hardness desired is between 45 to 55 Rockwell C, and should be measured 0.062in (1.6mm) from the cutting edge.

What are some applications of heat treating?

Through hardening treats the entire part and is used on medium and high carbon steels for moderate strength and surface hardness. Because through hardening requires a deep penetrating heat that can damage the surface of a component if not regulated precisely, induction heating is an excellent solution for this application.

Case hardening treats the part’s surface area and some of the interior area, according to the depth of hardening requirements of the application.

How can induction be used in a hardening application?

Induction can be applied to harden many types of cast irons and steel alloys.

10 Induction Heating Application Notes

Induction Heating Volume 1We have collected these 10 popular Application Notes to help you understand the many ways induction heating can improve your heating processes.

10 Automotive Application Notes

Automotive Manufacturing Vol 1 600We have collected these 10 popular Application Notes to help you understand the many ways induction heating can improve your precision automotive manufacturing processes.

Other hardening Resources:

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