Features: Professional countersink drill bits set crafted from high carbon chromium steel ensures superior durability and precise drilling in medium hard materials with 82° five flute design. Helical debris discharge slots minimize friction and heat buildup during operation, delivering cleaner cuts while for standard drills via universal 1/4" to 3/4" hexagonal shank sizes. Ideal for metalworkers, carpenters, and DIYer enthusiasts requiring reliable tool for industrial projects or home workshop applications. Perfect for drilling smooth holes in fibreglass plastic, aluminum sheets, hardwood surfaces, or mild steel plates without burrs or uneven edges. This comprehensive set includes five essential sizes (1/4" to 3/4") with heat treated blades for extended lifespan, making it a versatile addition to any tool collection. Specifications: Component:Steel Length:Approx.5cm/1.97inch Design: 85 degrees 5 blades Package Includes: 5pcs Countersink Drill Bit 1pcs Connecting Rod note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you donot mind befores you order. 2.Due to the differences between different monitors, the picture may not reflect the actual color. Thanks for your understandings.