The irwin 19 piece metric hss professional drill bit set offers industrial quality with outstanding performance and a long service life suitable for drilling steel and steel castings alloyed and non alloyed steel cast iron non ferrous materials plastics and other materials the 118 split point shape provides optimum centring when starting and a faster drilling rate supplied in a hardwearing metal storage case sizes 1 15 2 25 3 35 4 45 5 55 6 65 7 75 8 85 9 95 and 10mm