Hi,
I have been experimenting with different arrangements.

The coil needs to be about 40mm in diameter, big enough to easily fit over the tool holder nose, but small enough that there be good coupling from the coil to the tool nose.
The coil needs to be about 40mm long, again to suit the tool nose of HSK tool holders. this suggests about ten turns of 2.5mm/3mm wire (or copper tube) and in turn results in an
inductance of 2.5uH.

I have found and purchased a 4uF 1200V polypropylene capacitor made for induction purposes.

The combination should result in a tank that oscillates at 50kHz....which I think is about the sweet spot for the through heating I want.

I have researched various ZVS circuits, and they have the advantage of simplicity, but am more inclined to use a Hall current detector, or a CT, and use ZCS instead.
Also contemplating using a genuine H bridge rather than a half bridge as is common.

I already have an isolated high voltage, high current, high side MOSFET switch circuit that I use for high and low side switches for servo/motor drives. What may not be apparent
from the pic is that the circuit board used for this switch has a very thick copper layer, 420um or 12oz copper. Thus the high current traces on the underside of the board can handle 48A continuous.
The MOSFET is 650V....so this board was always designed and destined to be used at 400VDC to 450VDC levels and at north of 75kHz.

A genuine H bridge then does not really require any extra work as I already have a design, tested and ready to rock.

Craig