Review on Counterbore Set by Drill Warehouse by Matthew Riley

Honestly I don't know what makes a good countersink from a bad one other than just not doing what it says target. I'm happy to report that these bits work very well (I've only used them on wood) and are very easy to control. They have no problems with unguided holes or recessed cavities. I did notice that the cutter sometimes caused some abrasion to the fibers in the wood, but nothing that couldn't be fixed in 5 seconds with a 120 grit.