[QUALITY]: Made with heavy duty High Speed Steel for powerful punching and drilling of clean holes. []: Coated in Titanium Nitride for maximum durability. [EFFICIENT]: 1/4 inch Quick Change Hex Shank to fit most drills and drill presses securely. [CONVENIENT]: Two-Flute Spiral Grooved Design deburrs chip, dust, and debris for faster and smoother cutting. Titanium Nitride coating ensures the bit stays cool, reduces friction, and stays to last through countless drills. Quick Change Hex Shank makes it easy for bit switches and is compatible with most impact ready power tools, electric drills, and bench drills 135 degree Split Point Tip increases cutting speed with self-centering and prevents walking Its 2 Flute Spiral Design clears particles while drilling to decrease friction and heat for a cleaner and quicker process 5 pieces and 50 Step Drill Bit Sizes: 1/8 inch - 1/2 inch 1/32 inch increments (13 step drill) 3/16 inch - 1/2 inch in 1/16 inch increments (6 step drill) 3/6 inch - 7/8