5% Cobalt Drill Bit Set (1/16-3/8 Inch, 21Pcs) For Stainless Steel, Hard Metal, ?Premium 5% Cobalt Steel with 68 HRC? This Fully Ground Cobalt Drill Bits Set are Made with 5% Ture Cobalt. Although the Cost and Price are Slightly Higher, With a Useful Life,Heat,Wear and Chip Resistance up to 3 Times Longer than the Average Product. ?3X Efficiency + 3X Tool Life?This Cobalt HSS Drill Bits Set is Typically Capable of Running 3 Times Faster. Despite the Higher Price,the Cost Per Hole When Using Cobalt Drill Bit Will be the Lowest,Since It Can Produce So Many More Holes. ?Split Point Design with Unparalleled Precision?This Heavy Duty Work Drill Bits Kit is Suitable for Steel, Stainless Steel, Cold Rolled Steel, Hard Metals, Aluminum Alloy, Hard Wood, and Plastic, and Drilling Out Bolts Studs and Screws. ?Sturdy and Durable Metal Case?Different from the General Metal Case, This Drill Bits Case is Made of Q235 Cold Rolled Steel Plate, which Can be Opened and Closed Smoothly to Take the Drill Bits out at Any Time. ?21 Pieces Jobber Length Industrial Drill Bits Includes?:1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 11/64, 3/16, 13/64, 7/32, 15/64, 1/4, 17/64, 9/32, 19/64, 5/16, 21/64, 11/32, 23/64, 3/8 [DIA 1/64 Inch Increments]