Practical engraving drill bits: the package comes with 5 pieces wood carving and engraving drill accessories, and 10 pieces HSS carbide rotary burr bits, enough to use, and help you to make kinds of crafts without breaking the wood, to bring you smooth finished effect material: made of high speed steel material, and sturdy to use, not easy to break, offer nice cutting power to use; 15 Different shapes of bits are intended for faster wood removal, you can easily work with woods more faster while leaving a smoother ; Fit for grinding, polishing, shaping and burnishing , plastics and rubber surfaces Different sizes to choose: our carving drill bit measures . 3 x 3 mm, 3 x 4 mm, 3 x 5 mm, 3 x 6 mm, 3 x 8 mm in shank and bit diameter, the router measures about 1.5 inch/ 39 mm long, and the handle diameter is about 3 mm; Please allow a little error on the size due to manual measurement Convenient to use: all shank size is 3 mm, allowing them to be compatible with most grinders and rotary