6 Sizes: M3X0.5, M4X0.7, M5X0.8, M6X1, M8X1.25, M10X1.5. . 6 Steel Drill Bits, Suitable For Drilling Wood, Plastic, Fine Copper, Aluminum And Other Soft Metals (5-6 Mm), Not For Hard Materials (E.G. Sheet Steel). . Practical Connections, 1/4 Inch Hexagon Shaft, Quick And Easy To Change. Self Centering Point, No Need Help To Drill Or Punch The Center. Simultaneous Drilling And Tapping In One Step. Greatly Reduce Processing Steps, Save Time And Improve Work Efficiency. . When Drilling A Hole, Water Must Be Injected At The Same Time To Cool The Drill. This Will Help You Add Value To The Didactics. If It Is Not Possible To Cool The Drill While Drilling, The Drilling Speed Should Not Be Too High And You Do Not Have To Drill Too Often. . Composite Tap Is Preferably Used On A Bench Drill Or Tap. The Thickness Of The Piece Is Less Than 5Mm. When Used, The Lubricant Is Applied To The Faucet. When Using The Hand Drill, The Thickness Should Be Less Than 2Mm, Otherwise The Tap Will Break Easily (Because The Hand Drill Cannot Always Be Operated Vertically And Constant Speed). .