How to make keyway(hole)?

[vvtoshev]

Hi everyone i need to make keyway(don't sure thats the write word if have any germans speakers - Passfedernut).
I need to make the three holes on top and I don't know how.Does anybody have an idea?

[JonathanHodgson]

For each one, I would probably offset your plane "XZ_T_OBEN" and then extrude a cut upwards, sketching on the offset plane.

Unless the planes "PASSFEDERNUTEN" have already been created for that purpose, in which case sketch on them instead!

[vvtoshev]

They don't come right.So probably i don't give right dimension or something like that.Or I don't draw from the right place.
Never mind I get it should go through the center line.
Thanks any way.

Another problem :
Pop up another problem can't make any hole through the detail. Also the standart hole ISO M8x1 doesn't give me 8 diameter only 0.2323 or other minimal diameter.