ITEM NAME:4Pcs #6 #8 #10 #12 HSS Countersink Drill Bit Set Screw 1/4 Hex Shank Wood T #gib Store Home Promotion Hot Item Add to Fav.Drilling length can be adjusted for various length screws simply by loosening and tightening the setscrew. Drill and countersink for wood screws without changing bits. Black Chamfer Drill Body Material: Steel #45.