Description: Drill 28 Hole Sizes Step Drill Bits with organizer bag This compact Set Replaces 28 Individual Drill Bits Automatically Deburrs Holes as you Drill Two-flute Design Gives You Faster, Smoother Cutting Titanium Nitride Coating for Cooler Running Quick-change 1/4 Hex Shank High Speed Steel for Long Life These Step Drill Bits are ideal for variety of materials from metal, plastic, fiberglass to wood They also help to enlarge existing holes The two flute design tips made the penetration faster without chipping Specification: Sizes of the 3 Step Drill Bits: 5 Step Bit from 12mm to 4mm 9 Step Bit from 12mm to 3mm 13 Step Bit from 20mm to 4mm Weight :0.11kg Package included: 3X Step Drill Bits 1X Automatic Center Punch 1X Case