The BlueSpot 99 PCE Cobalt Drill Set is manufactured from M35 steel for increased speed and effective cutting, even at high temperatures. The drill bits are finished with a 135° split point, which is ideal for the cutting of sheet materials, and reduces the chance of the bit slipping during use, the 5% cobalt content also makes the drills better at drilling in harder materials. As normal when drilling in steel and stainless steel we recommend that you use a cutting fluid and centre punch when starting the hole. The set is supplied in a metal case for easy storage and transportation.Package Contents - 1.5mm 16 PCE, 2mm 1 6PCE, 2.5mm 15 PCE, 3mm 10 PCE, 3.2mm 10 PCE, 3.5mm 8 PCE, 4mm 8 PCE, 4.5mm 3 PCE, 5mm 3 PCE, 5.5mm 2 PCE, 6mm 2 PCE, 6.5mm 2 PCE, 8mm 2 PCE, 10mm 2 PCE.Manufactured from M35 steel for increased speed and heat performanceIdeal for the drilling in thicker and harder materials135° split point for increased accuracySupplied in metal storage case