A-Z 26 Piece Cobalt Screw Machine Drill Bit Set. Screw machine drills are also know as stub or stubby drills. They have a short, rugged construction performs well in a broad range of materials. Cobalt drill bits are are effective in drilling tough, high tensile strength materials. Display high red hardness, permitting speeds up to 30% greater than with conventional M2 high speed 135° split point tip for fast penetration and accurate drilling. Sizes smaller than 1/16 or #52, and larger than 1/2 have the 118 standard point. Popular in the automotive and construction industries. They are often used in screw machine setup where spindle clearance is limitedScrew machine drills are also know as stub or stubby drills. They are often used in screw machine setup where spindle clearance is limited.