8pcs Twist Drill Hole Bit Set HSS High Speed Steel Metal Tool Quick Change 4-10mm Product Feature： 4241 High-Speed Steel： Twist drill bits made from 4241 High-Speed Steel, which increases wear-resistance, durability, and extra long life span, so that the drill bits last through multiple uses 135°Split Point：135°quick-cut pilot split points are self-centering and can penetrate quickly with less pressure. The straight shank of this steel drill bit allows for firmly holding and accurate centering and makes drilling precise and faster Fully Ground Process： Fully ground spiral groove design clears particles quickly, decreases friction and heat for faster drilling performance Professional & Widely Use：Drill bits perfectly Suitable for drilling holes as Aluminum, Copper, Wood, and Other Softer Metals. Not for Glass or Ceramic Materials. Easy Use & Storage：This metal twist drill bits set includes 8pcs 20mm Drill Bits, This drill bit fits the majority of power drill currently on the market, easy storage and DIY, household maintenance, and repair. Product Specification： Type：HSS Drill Bits Set Length：200mm Size：10mm+8mm+6mm+5.2mm+5mm+4.5mm+4.2mm+4mm Set Includes：8 drill bits Material：4241 HSS Suitable for：Drilling holes as Aluminum, Copper, Wood, and Other Softer Metals. Package Included： 8Pcs HSS Drill Bit Set Note： Always wear safety goggles and safety items when drilling Do not wear gloves to avoid the hazard of getting caught in the tool and pulling your hand in to get mangled during bit spinning Examine the bits before use for cracks or chips, Do not use damaged or bull bits