Description DeWalt premium carbide percussion hammer bits are used primarily for drilling small diameter holes in masonry, concrete, rock, and artificial stone. These bits are used primarily to drill holes for mechanical anchors and fit into standard 3/8 In. and 1/2 In. chucks. With an innovative tip that reduces walking for improved accuracy.Carbide materialSpecially designed to reduce bit bindingInnovative tip configuration reduces walking for improved accuracyImproved carbide tip provides durabilityROCK CARBIDE tip maximizes surface contact for longer bit lifeThree flats on shank eliminate bit slipping in chuckFour flute design cleans debris out for fast, efficient drilling