Complete Range of Sizes? :’s 115-piece set includes 29 fractional sizes from 1/16″ to 1/2″ in 1/64 increments, 26 letter sizes A to Z, and 60 numbered wire gauges from #1 to #60. The included metal case makes it easy to store and transport your drill bits. The labeled compartments keep each size organized and quickly accessible. M35 HSS+5% Cobalt? : Made of high-speed steel with 5% cobalt, these drill bits are harder and longer lasting than typical HSS bits. Perfect for precision drilling in stainless steel and other hard materials. Optimized Design? : Featuring a 135-degree split point design, these bits have a blunter angle for more cutting edge contact and faster drilling. The twisted shanks also help clear metal shavings for easier drilling. Versatile Applications? : Not just for hard metals like stainless steel and cast iron, these bits can also tackle soft materials like wood and duroplasts. Truly a versatile set for any DIY or professional project. We stand behind our products and are committed to your satisfaction.