The Primo cobalt twist drill is sold in a three-piece assortment.  You get the point five millimeter, the 1.0 millimeter, and the 1.5 millimeter.  They're made of solid cobalt.  These are two-sided which extends the life of your bit.  They provide a pinpoint location to mark the area to be drilled.  I find that these are great for drilling out bearings and stone setting. Go to Stuller.com to find the Primo cobalt twist drills and other useful tools today.