Review on 🔧 YUFUTOL 20pcs Solid Carbide Burr Set 0.118‘’（3mm）Shank Tungsten Carbide Rotary Files Burrs with 3mm Cutting Head Diameter for Woodworking, Engraving, Drilling, Carving - Compatible with Most Rotary Drill Die Grinders by Steve Griffin

Used on broken bolts. I broke 1/4? screw on small motor (throttle lever). I then broke the bolt extractor into the broken bolt. I used them to carve the bolt and bolt extractor. When I finished the beat was a little lackluster (but still worked), but it was better than I expected. I also broke a 3/8 head bolt: on the same motor (8hp flat head). I used a drill to carve a 1/8" (burr size) center stop about 1/2" deep down the center of the bolt as a guide to drill out the rest of the bolt. This set has different shapes. Some of them can grind the tip which I used to cut right down the center of the bolt). The same drill bit has a cutting surface on the side so once inside you can move to the side to cut more.