3 Piece Heavy Duty Step Drill Set includes 1 piece each (1/8-1/2 In, 1/4-3/4 In, 3/16-7/8 In). Drill fast, bur-free holes in sheet metal up to 1/8 inch thick. Impact ready 1/4 inch hex shank for convenient use in impact drivers. Titanium nitride coating extends tool life and increases tool performance. Self-starting split point for accurate drilling- drill will not slip on work piece. Two flute design for balanced, clean holes. Ideal for electrical work.