Drill America Qualtech 33 piece 118 degrees conventional point general purpose drill bit set comes in a metal case. Expands the size range capacity of a portable drill chuck. Common flute and overall length for minimal adjustment during tool changes. Precision ground for high degree of concentricity between shank and body diameter. Ideal for drilling in low and medium tensile strength materials. High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance. Black oxide treatment adds lubricity and creates small pockets on the surface of the tool that act to hold coolant near the cutting edge. Round shanks allow use with a wide variety of toolholding systems. When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging. Set include fractional sizes: 1/2" to 1" (1/64 Increments). 1/2-inches reduce shank.