Description: Portable: Easy to operate and carry. Small in size and light in weight, it can be put in a tool bag and taken anywhere. Applicable: Straight design is better for many electric drills and drills, sharp and twisted grooves will make drilling easier to use Package and size: 100pcs drill, 1mm//0.04inch diameter Material: Drilling tools are made of high speed steel for high hardness and durability. Widely Use:Great for DIY, home and general construction, engineering use. Very suitable for drilling and reaming of aluminum alloy, wood, jade, diamond, bodhi Size Chart: Diameter:0.1cm/0.04inch Twisted Position:0.15cm/0.06inch                            0.2cm/0.08inch                            0.25cm/0.1 in                            0.3cm/0.12inch Package Includes: 100 Twist Drill(4 Pack) Note: Please allow slightly errors due to manual measurement and different monitors.