[High speed heat treated steel]countersink drill bits are made of high speed steel, QUENCHING treatment, so they are HIGH HARDNESS, WEAR-RESISTING and sturdy. [Different Sizes]Countersink drill bit set included 5 kinds of sizes:2.8 x 8mm, 3.0 x 8mm, 3.2 x 8mm, 3.5 x 8mm, 4.0 x 8mm, very suitable for using to multi size wood hole drilling. One tool for multi uses, improve your working efficiency. [Three Pointed Design]Quickly and accurately drill a smooth hole. Better in centering and no skid.Five-edged chamfer design will fast discharge chips from the hole on both sides automatically.It can effectively prevent the accumulation of debris retention, improve the drilling efficiency. [Wear Resistant]Countersink drill bit provides superior cutting capability, high durability and good wear resistance. [5 PCS Countersink Drill Bit Set]Countersink drill bits make perfect countersink holes for flat head and plug screws, eliminating the need to split wood and allowing you to enjoy clean engineering with the drill set. SPECIFICATION: Item Type: 5 Pcs Countersink Drill Bit Set Basic Parameters: Specification: 8x8x4; 8x8x3.5; 8x8x3.2; 8x8x3; 8x8x2.8 How to Use: Install and use directly. Colour:As Shown Material:Metal Package Contents: 5 x Countersink Drill Bit