The extractor is used in conjunction with a matching drill bit for faster extraction, the drill bit is punched out and then the extractor is used to remove the broken screw. Strong thread drilling is more powerful. Before taking the broken screw, drill the hole with the drill bit and then remove the screw easily. High tenacity steel thread, suitable for grade 8.8 ~ 12.9 stainless steel bolts, don't worry about not removing. Complete tools, you can use it yourself, with small size, easy to carry and store, convenient to use and with good performance. With strict quality control and quality assurance, a high safety factor can be used with peace of mind. Functionality: 1. The puller is used in conjunction with a matching bit for faster extraction, the bit is punched out, and then the puller is used to remove the broken screw. 2. Strong thread drilling is more powerful. Before taking the broken screw, drill the hole with the drill bit and then remove the screw easily. 3. High tenacity steel thread, suitable for grade 8.8 ~ 12.9 stainless steel bolts, don't worry about not removing. 4. Complete tools, you can use it yourself, with small size, easy to carry and store, convenient to use and with good performance. 5. With strict quality control and quality assurance, a high safety factor can be used with peace of mind. Specification: Item type: set of grub screw extractors Material: chrome-molybdenum steel, high speed steel Purpose: broken screw extractor, easy to remove difficult screws a & gt; Extractor specifications Extractor diameter (approx.) Pilot hole drill size (approx.) 1 # Extractor 3 ~ 6mm / 0.1 ~ 0.2in 1.93mm / 0.1in 2 # Extractor 6 ~ 8mm / 0.2 ~ 0.3in 2.94mm / 0.1in 3 # Extractor 8 ~ 11mm / 0.3 ~ 0.4in 3.96mm / 0.2in 4 # Extractor 11 ~ 14mm / 0.4 ~ 0.6in 6.37mm / 0.3in 5 # Extractor 14 ~ 18mm / 0.6 ~ 0.7in 7.43mm / 0.3 in Package list: 1 x key 5 x Extractor 5 x Drill 1 x Toolbox