Countersink Drill Bit Set: the 5 pcs woodworking counterbore hole drill bits set includes five commonly applied sizes of countersink drill bits - 4 (7/64 inch), 6 (9/64 inch), 8 (11/64 inch), 10 (3/16 inch), 12 (7/32 inch), a 1/4 hex shank quick replacement bit holder, and a hex wrench; These sizes are suitable for the needs of cabinet and furniture makers, as well as woodworking or beginnersCutting Depth Adjustable: the counter sink drill bits involve two adjustable screws that can be moved up or down the shank of the bit to limit how far the drill penetrates into the material; The adjustable counter sleeve depth can be easily modified using the included hex wrench, ensuring a precise control over hole drill depth and enhancing the functionality and usability of countersink drill bit setsIncluded Quick Replacement Bit Holder: the 1/4 inch hex shank magnetic drill bit holder serves as a convenient accessory for quickly swapping out countersink drill bits during drilling operations, whose extended torsion zone can help absorb the high torque of impact drivers, ensuring you that your bits stay in place and never wobble while in use, good for working with hard to reach screwsImportant Tips: 1. that the drill and workpiece are properly aligned before drilling; 2. Choose the appropriate drill speed based on the material; 3. Cool down excessive heat buildup while drilling; 4. Regularly inspect depth settings of the counter sleeve with different materials or changing bit sizes; 5. Check drill bits for any signs of damage or wear before drilling; 6. Clean and Store the drill bits after each useProduct: Countersink Drill Bit SetNotes:The color may exist a slight difference due to different screen displays.Pointed items are included, please be careful when using and please keep them away from kids.Colour:BlackMaterial:ALuminum AlloyPackage Contents:1 set x countersink drill bit setOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.