Features Features: - Drill bit material: HSS Sizes: 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3.5 mm, 4.5 mm, 4.5 mm, 5.5 mm, 5.5 mm, 6.5 mm, 6.5 mm, 7.5 mm, 7.5 mm, 7.5 mm, 7.5 mm, 7.5 mm, 5 in, 0.0 315mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm. / 12.5mm/13mm Quick description: 1. When drilling steel parts, make sure to cool enough and use metal cutting liquid. 2. Make sure the magnetic base and workpiece are level and clean. 3. When drilling thin plates, reinforce the workpiece and, when drilling large workpieces, make sure the stability of the workpiece. 4. At the beginning and end of drilling, do not turn the drill bit to work, but keep a parallel motion, and the feed rate should be reduced by 1/3. 8. For materials that have a lot of fine dust during drilling, such as cast iron, molten copper, etc., you can use compressed air to help remove chips without using coolant. 6. Remove the rolled iron files on the drill body in time to ensure smooth chip evacuation. 7. After use, it should be washed, dried with a damp cloth and coated with anti-rust grease to prevent rust. Package includes: 1 set of 25 HSS helical drill bits. Package List