Thanks to my knowledge gained in practice, these metric drilling bits have been a game-changer in precision drilling .The cobalt composition guarantees long-lasting durability and sharpness to complete any project with ease. The straight shank design enhances stability and the metric sizing ensures accuracy for consistent results. The only con is that they come in a limited set of sizes, but for the ones included they are top-notch. Highly recommend this product for any industrial and scientific drilling needs!