Induction hardening serves as one of the best mass production processes used recently due to its ability to quickly generating high-intensity heat in a well-de ned location of the part. Numerous advantages of this method make it a reliable technique to produce a thin martensite layer on the part surface that has compressive residual stresses. In this regard, the presented study is devoted to investigating utilizing induction heating for surface hardening of AISI 4340 steel disc. The purpose is to evaluate the performance of magnetic ux concentrators and the effects of the induction process parameter on the case-depth and edge effect in the surface hardening of the disc. Once the proper range of parameters is de ned, Taguchi experimentation planning is used to frame comprehensive experimentation with the minimum possible trial. Then, the case-depth of discs is evaluated on their cross-sections (edge and middle plane) through hardness pro le measurement of samples using a micro-indentation hardness machine. The results are then statistically analyzed using Analysis of Variance (ANOVA) and Response Surface Methodology (RSM) to determine the best combination of parameters to achieve maximum casedepth yet minimum edge effect. The goodness-of-t regression models are then developed to predict the case-depth pro le as a function of machine parameters based on linear regression utilizing case-depth responses in the edge and middle plane of discs. Results imply that maximum case-depth with minimum edge effect can be produced by using the highest heating time along with the average amplitude of the power, axial gap, and radial gap. This study gives a good exploration of case-depths optimized by setting up process parameters when magnetic ux concentrator is utilized, thus, a guideline to reduce discs edge effect in induction surface hardening application is given.