Akozon 5pcs M3-M8 Slotting Counterbore End Mill Cutter Solid Slot Countersink End Mill Drill Bit

I purchase several things on Amazon and was giving pretty in-depth reviews. From this point on, here's the new agenda…. if it works as advertised, is well made, meets or exceeds the description, is a value, and arrives in a fair amount of time, it will get a "star rating" equal to what my expectations were/are. If it doesn't meet these criteria, then I will most definitely and descriptively tell the short comings of the products and you as a consumer will not have to go through the trouble of buying the product without some background knowledge. If the sell pulls that item and relists under another description, I will put the exact same review on the seller's feedback page. Sellers have done this a couple of times in the past, and I was true to my word then as well as now. DR

does a real good job of counterboring holes

They are sharp and work well.

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.

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.

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