At 1mm these are very small drills. We've only used them to drill a lot of holes in PVC so they worked great in that material. We only broke two. I don't know how they will perform on harder material. Maybe that's one of the reasons you need to buy 20. :)
Bit and socket set BOSCH Promoline (2.607.017.322), 26 pcs.
24 Review
๐งฑ Bosch 2607017164 Piece Setter Masonry: Advanced Tools for Precision Masonry Work
20 Review
Tool set Stels Tool set, 1/2", 1/4", CrV, plastic case 94 pcs, Stels, 94 pcs, black
45 Review
Tool set Ombra OMT94S12, 94 pcs, brown
27 Review