Drill America Black & Gold Contractor Grade Drill Bits are manufactured from M1 high speed steel. These drills are for use in a wide range of materials in the iron and steel families such aluminum, iron, steel and other metal drilling. They have a 3-Flat shank which creates an extra secure hold in your chuck. The 135 degree split point tip helps with accurate drilling. Compared to a conventional 118 degree tip, these drills wont go "walking" on you.