The Metabo HSS-Tin Drill Bit Set is suitable for drilling steel and cast steel, alloyed and unalloyed, grey cast iron, non-ferrous metals and plastic up to 900 N/mm² tensile strength. The bits are coated with a titanium nitrate alloy with a ground, cylindrical, type N, 135° crosswise grinding tip and gold coloured surface finish. They are NOT suitable for aluminium. They are supplied in a metal tin and it contains one of each size: 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 & 10mm.