15 High Speed Twist Drill Bits Great for Metalsmiths, Metal Working & Drilling. The is a new set of 15 high speed steel twist drill bits. Great for drilling ferrous metals, tough casting sand forgings, working hardened stainless steel and other hard steels and tough high tensile strength nonferrous metals like titanium. These bits measure approximately 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 and 1 mm (0.011", 0.013", 0.015", 0.017", 0.019", 0.021", 0.023", 0.025", 0.027", 0.029", 0.031", 0.033", 0.035", 0.037" and 0.039"). We work hard to update our descriptions and pictures of our merchandise. As part of a process of ongoing innovation by our suppliers, newer versions of the item shown may be shipped before we are able to complete an update. As a result there may be a slight variation in color and design.