Brass Countersunk Slot Metal Thread

I would countersink first and then create the hole and slot subtr Countersink created using Move with Auto Fold Hole and slot cut using

Screw Slot Bit

slot onine I am trying to create a slot that is countersunk for a flathead screw I know how to create a hole with a countersink, and I made the slots

sails of gold slot Trend WP-SCW31 M6x25mm Countersink Slot Machine Screw Replacement M6 machine screw