Set contains 29 cobalt drill bits. These heavy duty 135 degree split point, M35 cobalt steel, jobber length drill bits are 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. Drill set comes with a rust resistant, water and shatter proof case.