The Faithfull HSS taper drills are used for drilling sheet materials. They will drill a hole of any diameter between the stated sizes. Please note that use of a cutting fluid is advisable with this drill. The Faithfull FAITDSET3 taper drill set of 3 are made from high speed steel (HSS) consisting of: 1 x 4-12mm, 1 x 6-20mm, 1 x 16-30mm. The set is supplied in a metal storage case.