Hi Wong,
The 12mm c/bore, I am assuming the 7mm holes are for 6mm size screw.
Drill the holes 6.5mm diameter and c/bore using a 10mm end mill. Then turn the diameter of the cap head of the 6mm screws down to 9.5mm dia.
What do you think, I do it some times.
If you prefer to stay with the drawing and c/bore with a 12mm end mill, first do it with an 8mm, then a 10mm and finish with your 12mm end mill.
DaveH
PS that link to the pdf does not work for me. Also Ed beat me to it.
The 12mm c/bore, I am assuming the 7mm holes are for 6mm size screw.
Drill the holes 6.5mm diameter and c/bore using a 10mm end mill. Then turn the diameter of the cap head of the 6mm screws down to 9.5mm dia.
What do you think, I do it some times.
If you prefer to stay with the drawing and c/bore with a 12mm end mill, first do it with an 8mm, then a 10mm and finish with your 12mm end mill.
DaveH
PS that link to the pdf does not work for me. Also Ed beat me to it.