1. The hex drill bit is made of M35 cobalt high speed steel with sharp edge. The surface is coated with titanium, which has higher hardness, better wear resistance and longer service life than ordinary drills.2. 1/4 hex shank, which can quickly replace the drill bit, eliminates the frustration of the handle rotation on the chuck, and makes it easier to quickly lock to the chuck. It is suitable for most electric hand drills and drilling machines.3. The fully ground spiral groove design can quickly remove debris, reduce friction and heat, and drill faster. The 135 ° straight shank split point reduces walking on the working face, making drilling accurate and easy.4. Hex twist drill bits are used for applications such as DIY projects, and home maintenance. Suitable for steel, copper, aluminum, zinc alloy, cast iron, wood and plastic.5. Please keep cool and gentle using, the working life of the twist drill bits can be largely prolonged by proper usage. Size - Drill Diameter: 2.78mm / 7/64-inch, Drill Bit Length: 34mm / 1.34-inch, Shank Size: 1/4 Inch(6mm) Hex, Total Length: 85mm / 3.3-inch Material - The hex drill bit is made of M35 cobalt high speed steel with sharp edge. The surface is coated with titanium, which has higher hardness, better wear resistance and longer service life than ordinary drills. Feature - 1/4 hex shank, which can quickly replace the drill bit. The fully ground spiral groove design can quickly remove debris, reduce friction and heat, and drill faster. The 135 ° straight shank split point reduces walking on the working face, making drilling accurate and easy. Application - Hex twist drill bits are used for applications such as DIY projects, and home maintenance. Suitable for steel, copper, aluminum, zinc alloy, cast iron, wood and plastic. Note - Please keep cool and gentle using, the working life of the twist drill bits can be largely prolonged by proper usage. Set Name 12pcs Brand Name HARFINGTON Shank Type Hex Unit Count 12.0 Count Part Number hta240302hh000572 Finish Types Titanium Manufacturer HARFINGTON Material Type Cobalt High Speed Steel Tool Flute Type Spiral Cutting Diameter 2.78 Millimeters Number of Flutes 2 Cutting Angle String 135 Degrees Surface Recommendation Plastic, Wood