[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 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 Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.