General description Neilsen 3pc HSS Cone Cutter / Taper Drill Set is made from high-quality HSS steel, designed for cutting holes in a variety of materials including steel, brass, wood, plastic, copper, fiberglass, and PVC. The set comes with a convenient storage case. Technical specifications Material: HSS steel Sizes: 3 - 14mm, 8 - 20mm, 16 - 30mm