The cobalt cutters we purchased are exceptional! Based on our own experience, we can confirm that these industrial and scientific drill bits provide superior and precise cutting power, enabling us to efficiently cut through even the toughest of materials. The cobalt coating ensures that the drill bits last a long time which is a definite pro .The only con we can find is the price, as they are slightly more expensive than other options. However, the quality of the product is well worth the investment. Overall, we would highly recommend these cutters to anyone in need of reliable and effective cutting tools..