DeWalt DD4120B6 5/16″ Cobalt Machine Drill Bits 6Pcs.Made in GermanyPatented web taper is 2X larger than the competition for increased strength, rigidity and breakage resistance -Optimized 135 degree split point gives exceptional service life and also allows the bit to start on contact -Heavy duty flute design produces maximum durability -Increased cobalt content provides exceptional wear resistance and longer life