[ 11 STEPS ] Includes 1/4, 5/16, 3/8, 27/64, 31/64, 9/16, 39/64, 43/64, 23/32, 25/32 and 7/8 inch sizes allowing you to drill up to 11 holes with different diameters. [ M35 HSS STEEL ] Made from M35 High Speed Steel (HSS) for strength, durability (HRC60), accurate and precise drilling. Suitable for demanding drilling applications and can withstand higher temperatures generated during drilling which can lead to longer tool life and improved performance, especially in applications that generate a lot of heat. [ 2 SPIRAL ] Equipped with a 2 spiral groove and X-type opening to minimize friction during drilling, enhance chip evacuation by channelling debris away from the drilling area, provide added stability, process deeper holes and promote faster drilling speeds. 3/8 inch 3-sided shank for easy operation. [ HEAVY DUTY ] Industrial titanium coating for increased hardness (HRC60), wear and corrosion resistance, reduced surface damage, reduced friction and heat generation and fatigue resistance with clear and distinct sizing laser markings for high visibility. [ IDEAL FOR ] Drilling and enlarging holes, chamfering, deburring, 3mm stainless steel plates, 5mm iron sheets and aluminum sheets.