Features: 【Combo Set of 6 Sizes】 6 most commonly-used sizes to satisfy all your needs. This drill bits set fits the majority of power drill currently on the market and come with a portable plastic bag for easy storage and organization. 【M35 Cobalt High-Speed Steel】 Industry grade 6542 high-speed steel drill bit set, harder than 4241 HSS used in other similar drill bits set. These drill bits also contain 5% Cobalt, which increases wear resistance and durability. 【Fully Ground Process & 135-degree Split Point】 Fully ground spiral groove design quickly decreases friction and heat for a faster and cooler drilling performance. 135-degree split point with straight shank prevents walking and makes drilling precise and faster. No center punch is needed. 【Multiple Application】 Suitable for Cutting Hard Metal such as Stainless Steel, Steel, and Cast Iron as well as Wood, Aluminum Alloy, and Other Softer Metals, including tiles, concrete, tiles, bricks, wood, plastic, glass, masonry, and more. 【Work Efficiently】 The product has sharp edges and high drilling efficiency. The center of the product has sharp serrations, and with its help, the drill can continue to drill horizontally after drilling. 1. High-speed steel material drill bits can be stable and durable 2. Easy to install, suitable for most electric drill 3. Drilling needs matching with cooling liquid, cooling liquid is not included in the package. Usage Scenarios: 1. Suitable for holing, cutting on wood, soft metal, aluminum plate, iron, etc. 2. Suitable for drilling and cut grooving processing on thin wood plate, wood, aluminum, and plastic boards Item Type: Drill Bits Material: High-Speed Steel+Titanium Plating Structure: Saw&Drill Application: Woodworking, Aluminum Alloy, Plastic Board Drilling And Cut Grooving Product specifications: 3mm, 4mm, 5mm, 6mm, 6.5mm, 8mm This is a 3 in 1 serrated drill: Function 1: Can be used as a drill Function 2: Can be used as a sawtooth groove Function 3: Can be used as a saw blade on the surface of the wood Package list: 3Pcs drills Set B: 1pc * 6mm serrated Drill Bits+ 1pc * 6.5mm serrated Drill Bits + 1pc * 8mm serrated Drill Bits or 6Pcs drills Set C : 1pc (3mm+4mm+5mm+6mm+6.5mm+8mm) serrated Drill Bits Note: Please allow 1-2mm differences due to manual measurement, thanks.