M-35 Cobalt Construction for Durability in abrasive materials
Jobber drill bits have 135-Degree Split Point Tips for reduced bit walking
Straight shank works in both keyed and key-less drill chucks
Heavy duty spiral flute design produces faster chip ejection
Shorter cutting lips reduce torque for drilling in high tensile strength materials
The Irwin Tools 63116 1/4-Inch Cobalt 135-Degree-Jobber Length-Bulk - Pack of 12 is made of M35 Cobalt Steel. The cobalt steel helps discipate heat, which is the killer of all drill bits, providing it with longer life and more durability. The cobalt construction allows this bit to drill abrasive materials like Stainless Steel and Cast Iron which are extremely tough on traditional high speed steel drill bits. The bit has a 135-degree split point tip to help eliminate walking as you start to drill the hole in metal. The straight shank works in both keyed and key-less chucks.