Professional quality drill bits made in the USAManufactured of premium M2 high-speed steel which contains a higher percentage of critical elements (molybdenum and vanadium) making the drill bit harder and strongerLasts 3 times longer and drills 2 times faster than standard drill bits135? split-point drills on contact and eliminates walking135? split-point requires less force so you do not have to push as hardBlack and gold finish adds lubricity allowing the drill bit to run cooler and last longerSizes 3/16-inch and larger have flatted shanks which eliminates slipping in the chuckSizes larger than 3/8-inch have a reduced and flatted shank and will fit into 3/8-inch and larger chucks