Akozon5pcs M3-M8 Slotting Counterbore End Mill Cutter Solid Slot Countersink End Mill Drill Bit

They are sharp and work well.

I used this on UHMW so not sure how good it would Be on steel. For my use it was fine.

I haven’t started the project these were bought for.

This is a nice counterbore set. They cut very well.

These worked for me on some mild steel but I'm not sure how long they would last. Not the greatest quality but it got the job done.

Well made

I wouldn't use these on hardened steel, but they're great for aluminum profile, at much less than the cost of "real" counterbores. I use them for recessing metric socket-head screws in 20 mm aluminum extrusions. Note that the holes are deliberately not exact to the millimeter. The pilot hole is slightly oversize (since your main hole will be) and the outer hole is slightly under (all my screws fit perfectly).Each piece has its own cheap plastic box, which is better than some things I get where everything is dumped randomly in a bag.

Used it for counterboring, worked well.