X-wing head provides visibility and stability during operation. The center spur of each bit guarantees accurate drilling and prevents walking and wobbling during operation, create perfectly round and accurate holes with the center spur design. They can enlarge existing holes with ease and can bore any arc of a circle. Overlapping, angled and pocket holes in all types of wood, easy to drill the hinge hole, cylinder hole, computer desk threading hole, home cabinet attachment. Strong Performance.The woodworking are designed for use in Hardwood and softwood, Wood materials, Gypsum plasterboard. Suitable for drill, bench drill, vertical drilling machine hand electric drill. It is and more accurate to use this drill bit in a drill press. Carry Case Include.To keep your entire drill bit set in order, the set comes in a tough wood carrying case with on closures, Thus you can take it to anywhere you . 15 PC Bits Size: 10mm,12mm, 15mm, 16mm, 18mm, 20mm, 22mm, 25mm, 26mm, 28mm, 30mm, 35mm, 40mm, 45mm, 50mm. color:silver Material: 45 steel WARM TIPS 1. Always notice to add some Coolant (water) when operating in order to prevent the material temperature will very high or smoke. 2. If you the blades are not very sharp, you can sharpen as you . Package Contents: 1 x Drill Bit Set Only the above package content, other products are not included. Note: Light 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.