Difference between tooth-by-tooth and pass hardening: When to use one and when to use the other?

In a recent article, we talked about the differences between the different materials used for our products and their efficiencies by virtue of their applications.
Both of these materials (C45 of SAE1141), being carbon materials, lend themselves to receive a thermal treatment called induction hardening.

What is induction hardening?

It has to do with sudden and localised thermal processing of a material, via high or low frequency inductor.
The material is heated rapidly bringing it to between 900 ° and 950 ° and then it is rapidly cooled. The temperature at which the steel is heated and the time it remains at this temperature, enables the structure of the starting material to become fully austenitic.
The purpose of this process is to obtain very hard surfaces which have a high resistance to fatigue and wear. It is essential to provide the materials with a high resilience, high elasticity and, in general, a high mechanical resistance.

What is pass induction hardening?

Induction hardening is used for medium and small to medium modules.
Gambini Meccanica guarantees certain performance results with technology that has passed a maximum of 4 modules.
The penetration of hardness expressed in HRC or Vickers (HV) is effective and meets the demand of the market prerogatives. The component is adequately designed to meet the requirements.
With more modules, this hardness injection technology would not guarantee the correct performance, because the tooth has a larger geometry.
From module 5 to module 40 and beyond, we use a different technology called tooth by tooth.

What is tooth by tooth induction hardening?

Where in pass hardening technology the inductor flows over the piece, in tooth by tooth hardening the inductor travels between one tooth and another. It is a longer process that guarantees adequate treatment and optimal performance results to the tooth surface.