Bosch Drill Bit HCD2081 SDS Plus Speed Clean 1 2 x 9 Inch Hollow Concrete Masonry (Hollow Dust Extraction Core 4.25 In Usable Adhesive Anchor Boring) Hammer Drills The Freud 87 308 3 piece CNC The Freud 87 308 3 piece CNC router bit set carves intricate three dimensional topographical reliefs Workshop Efficiency: Reducing production cycles by eliminating secondary edge jointing or sanding operations on rip cut stock this hollow extraction bit connects to jobsite extractors using the included rubber adapter Solid Carbide Two Cutter Head: Thermally brazed carbide cutting tip maintains hole diameter accuracy and provides service life comparable to solid drill bits