Beveling face of model

[Gully_Foyle]

Pretty much as in this other recent discussion:

Drill a horizontal hole in an angle surface with flat area for bolthead and nut

Create a stepped cylinder representing the two diameters of the counterbore. Position the stepped cylinder in the board where the counterbore goes, then right click the selected cylinder > Intersect Faces with Model. Then remove excess geometry. -Gully

-Gully