Fangrui Product Details Comprehensive Kit: This Set Includes 30 Dual-ended 3/16 Inch Coballet Drill Bits, Extensive Drilling Requirements. Optimal Operation By Maintaining Moderate Speed, Pressure, And Cool Temperature During Use To Enhance Bit . Precision Crafted: Each Bit Measures Approximately 1.89 Inches In Length, Crafted From Robust M35 High-speed Steel. Their Construction Ensures Durability, Resistance To Heat, And Minimal Wear, Allowing For Precise And Stable Drilling Every Time With Drills Including Lithium, Hand, And Impact Drills (not Included). Enhanced Efficiency Design: Featuring A Double-ended Twist Design, These Bits Offer Two Cutting Points To Separately Drill Holes, Doubling Your Work Efficiency. The 135-degree Split Point And Twist Shape Promote Faster Drilling And Precision. Versatile Utility: Suitable For Piercing Through Tough Materials Such As Stainless Steel, Titanium Alloys, Cast Iron, And Hard Plastics. These Bits Also Gracefully Handle Softer Materials, Making Them An Essential For Both Profes