Drill Bit Set 115 Pcs Includes 29 Pcs Fractional Sizes From 1/16″ To 1/2″ By 64Ths Increments; 26 Pcs Letter Sizes From A To Z; 60 Pcs Wire Sizes From #1 To #60. This 115 Pcs M35 Twist Drill Bit Set Meets All Your Needs. High-Speed Steel M35(Cobalt 5%)Cobalt Drill Bit Set Can Effectively Drill Tough And High Tensile Materials. The Metal Drill Bit Is Especially Suitable For Cutting Hard Metals, Such As Stainless Steel, Cast Iron, Superalloys, Titanium Alloys, Rigid Plastics, And Wood, It Can Also Be Used In Soft Materials. The Twist Drill Bit Is 135? Split Point With A Round Straight Shank, Self-Centering Prevents Walking, And Makes Drilling Precise And Faster. Double Back Angle Process And Full Grinding Process Is Adopted Fully Ground Process Twist Des.