Keyhole T-Slot Pockets for 4mm screws

3mm Upcut bit T-Slot Bit Panhead 4mm Screws with head dia ~7.75mm or anything possibly close to 8mm is fine.

I might be wrong about the name of the router bit. So correct me if there's a better/more correct word for it. The center of the screw will be 10mm of the top and the sides of the outer guide square. You can use this to align it to your workpiece at -10/-10 of the point you need it to be. The files provided are based on my measurements that I used to create the cut file, review and adjust depending to your router bit before cutting. The bits I use are both from ENT, T-Slot Router Bits, 8mm Shaft Variant 1 is 8.5-5.6x47x8 Variant 2 is 10.5-6.6x48x8 1. 

Helix out the Circle Shape to depth of your big diameter cut height (in my case 4.7mm) plus the rest of material you want to keep (in this example I would choose 10mm if my stock has the suiting thickness, so i have 5,3mm for the screw) 
using first a 2mm and then a 0mm offset with the 3mm or 6mm (for the bigger version) cutter. This makes this step a very fast two cut-operation. 
 2. Change bits to your T-Slot cutter. As we do cut along the line, Origin does not need to know that we changed the bit size. So you do not need to change any cut settings and cut along the line, but please take a second now and read to the end before you start: It is important to consider BEFORE CUTTING that you do NOT Forget to Z-Touch and that if your bit retracts anywhere outside the area of plunge+retreat it will cut through material you want to keep. So don't. It happened to me and while my bit or Origin were not damaged visibly, it was not a good experience for the work piece… 
Make the On-Line Cut with the Keyhole-Router Bit, plunge and retreat at the lower end of the line, that's the end in the middle of the lower circle.
 Cut depth remains the same as above. Let Origin plunge all the way down before staring to move carefully along the line. Best choice is probably using the auto-cut function at a decent speed setting (I used default) to cut the line up and down again. Make sure to keep a good grip on origin towards the middle of the cut when it changes direction! Do NOT retreat at any other point than the lower one. Disable Auto-Mode just before you reach the end of the line and ff you miss the point, just cut another round. ;) Make sure you are at the last point of the line before you retreat the bit. So this is a simple 3-step technique I found to be fast and reliable and produce surprisingly strong pocket holes for wall fixture of small furniture. The precise positioning as well as the helix pocket cut in 2 steps make it a quick method. The line could be draged out to a rectangle or reversed "U" for larger cutouts if you don't have several bits available. Update 2020-07-04: - added 6mm Screw Head File (Head Diameter 12mm). - added exact description of bits used