Description: MATERIAL: Made of quality HSS steel, high hardness, wear resistance, durable. FITMENT: Professional repair tool parts, excellent replacement for old or broken accessories. USAGE: The twist drill bit can be used for wood, iron, alloy, and other materials, perfect for home, office, and more maintenance or DIY project. INSTALLATION: Easy to install and remove, convenient to use. PRACTICAL: Portable drill bit set has multiple sizes, satisfying your different needs, ideal for carpenters, mechanics, artists, hobbyists, etc. Specification: Material: HSS Steel Size Chart: 13pcs: 1.5mm/0.06inch, 2mm/0.08inch, 2.5mm/0.1inch, 3mm/0.12inch, 3.2mm/0.13inch, 3.5mm/0.14inch, 4mm/0.16inch, 4.5mm/0.18inch, 4.8mm/0.19inch, 5mm/0.2inch, 5.5mm/0.22inch, 6mm/0.24inch, 6.5mm/0.26inch 19pcs: 1mm/0.04inch, 1.5mm/0.06inch, 2mm/0.08inch, 2.5mm/0.1inch, 3mm3mm/0.12inch, 3.5mm/0.14inch, 4mm/0.16inch, 4.5mm/0.18inch, 5mm/0.2inch, 5.5mm/0.22inch, 6mm/0.24inch, 6.5mm/0.26inch, 7mm/0.28inch, 7.5mm/0.3inch, 8mm/0.31inch, 8.5mm/0.33inch, 9mm/0.35inch, 9.5mm/0.37inch, 1cm//0.39inch Package Includes: Optional 13 Drill Bit Or 19 Drill Bit(6 Pack) Note: Please allow slightly errors due to manual measurement and different monitors.