Just cut 2 holes, the bit I used worked fine. I expect the others in the set will work well in the future. The time will show. It should be noted that many people seem unaware that an angle cutter requires low speed, constant pressure, and constant oil lubrication. If you deviate from this, you will overheat/destroy the cutter and get poor life and poor results. Cutters are expensive, oil is cheap, don't argue with oil.