How to choose the frequency of surface quenching of cylindrical workpieces?

How to choose the frequency according to the thickness of the quenching layer when the cylindrical workpiece is surface quenched by induction heating?

When the cylindrical workpiece is surface quenched by induction heating, the principle of selecting the frequency according to the thickness of the quenched layer is that the higher the frequency, the thinner the depth of the quenched layer, as follows:

The depth of the hardened layer of high frequency (100~1000kHZ) quenching is 1-2mm; the depth of the hardened layer of medium frequency (1~10KHZ) quenching is 3~5mm; the depth of the hardened layer of power frequency (50HZ) quenching is 10~15mm .