【Package & Size】 Size range: 1/16"x2, 5/64"x2, 3/32"x2, 7/64"x2, 1/8"x2, 9/64", 5/32", 11/64", 3/16", 13/64", 7/32", 15/64", 1/4", 5/16", 3/8", 1/2". Most frequently used size range with extra small size drill bits. All drill bits are kept in a strong and professional plastic case with indexed holder which is convenient for storage and pick-up..【Wide Applications】 VALYRIANTOOL Hex drill bit sets are built for general purpose applications, such as DIY projects, home maintenance and MRO (Maintenance, Repair and Operations). Working materials include mild steel, copper, aluminum, zinc alloy, cast iron, wood and plastics..【HSS Black & Gold Oxide】High speed steel (HSS) with black gold surface treatment gives VALYRIANTOOL Hex drill bits great durability and prolongs 3 times longer life than ordinary drill bits without coating..【135 Degrees Split Point and Parabolic Flute】VALYRIANTOOL Easy Cut Split Point design makes drilling easy with less pressure and prevents drill bits walking on the working surface. Fully ground modified parabolic twist flute design clears chips quickly, decreases friction and heat damage..【Quick Change Solid Hex Shank】1/4" (6.35mm) hex shank fits into standard power tools and impact drivers. VALYRIANTOOL Hex drill bit's solid bonding technology eliminates radial runout and improves concentricity. High torque, impact-rated accuracy.