How to use the Hinge bore bit:
The radius of the hinge bore is 17.5mm and it is also the centre point distance. It would be safe to have a 4-5mm shoulder from the side of the cupboard door. So the distance from the edge to start boring is 17.5+4.5=22mm.
Hardwoods require a slow speed when boring. The hinge bore can easily be sharpened using a diamond file.