When I opened the packaging and used it, it seemed to me that the drill bits were smaller than the pictures. However, all the pilot holes I've made are fine. as well as counter sinks. I've been using it for the last few days with no problems. I also thought that the sink size was smaller or larger depending on the drill, but they all have the same sink size. Just different drill bit sizes. When I started using the countersink didn't spin. Upon closer inspection I noticed that the hex bolt wasn't tight so I tightened it and haven't had any problems since. All in all a good set of countersinks. You will not be disappointed.