I use it for hole drilling of resin accessories by handicraft. It is appreciated that there are sizes of 1 mm each comma because there are various thicknesses of things to pass. Pinyus also purchased the same manufacturer's, so you can use it nicely.
Since it is extremely fine, it is measured with a micrometer to confirm the size. The size is very accurate. It is tough to turn it once because it is just arranged in a container. I think that it should be a container of a method to be put in a hole.
I used pinnipes of Annex, with three drills, but I also wanted a spare and the same size as the size difference I bought it. Right now, I am working to drill out the part of the hole of the cotton pearl that is blocked. There is no problem with the same 1 mm in Annex, but here, pulling the drill comes with cotton, the hole closes more than the original, even a thin needle will not pass. Is the smoothness of the drill surface different? Or did you choose a product and made a mistake? It's a set, so if you fail, it's big. As I mentioned in other reviews, I think that I will buy next time where I am selling individually.