3-In-1 Combined Tap/Drill/Countersink & Bit Sets saves time with the ability to drill, tap and deburr in one operation. The tandem-style drill/tap assures the proper drill for the tap size. Made of high speed steel for long tool life, but the use of cutting oil is recommended for best results. After completing the tap, reverse the drill to back out. For use with steel, copper, brass, aluminum and plastic. Standard and Metric sets available in blow molded case for protection and easy tool identification.