Cobalt jobber drills. Heavy Duty 135 Split Point, Cobalt Steel, Jobber Length, manufactured to National Aerospace standard 907. These drill bits display high red hardness, permitting speeds up to 30% greater than with conventional M2 high speed steel, and are especially effective in drilling tough, high tensile strength materials like stainless steel, inconel, and titanium. The 135 split point is self-centering and reduces thrust. Sizes smaller than 1/16? or #52, and larger than 1/2? have the 118? standard point.