KEO 53512 Cobalt Steel Single-End Countersink, Uncoated (Bright) Finish, 82 Degree Point Angle, Round Shank, 5/16 Shank Diameter, 1/2 Body Diameter

Works as advertised, smooth clean countering

Not bad

Great for use on wood. I first drill the pilot hole to the finished size, then use this tool to create a countersink. It cuts the wood very quickly and smoothly. It leaves no chatter marks the way traditional wood countersinks often do.

I bought this to counter sink the holes I was drilling for threaded inserts. When I first opened it, I wasnt expecting much, but it did great against red oak. Would purchase again.

Have been using KEO products for years. Had to hone the cutting edge a little when I got them but that was no big deal. Hope they last me as long as the last set, over 20 years. I’ve used them on all kinds of steel, including 416 stainless.

So far it works better that any other countersinks I own, should last a long time.

It makes a dang fine smooth tapered hole. Have several fanged countersinks in the box; all exhibit steps around the edges. This one, with the sharp circular hole, is a design achievement.

Great for softer metals and mild steel.

It works well

I bought the 10 dollar Irwin countersink. Hey its a cheap bit what can go wrong? Everything! The countersinks came out looking like a flower, ridges and valleys, horrible! Even clamped down with a drill press. Back to shopping for a better bit I found this, and it is like night and day. It repaired the horrible Irwin countersinks with ease and left shiny smooth round countersinks for my bolts to snug into. No idea how long it will last, but I will never go back to a finned countersink. the smooth base 1 hole types are where it is at. This countersink works great!