Titanium nitride (TiN) coated bits last up to six times as long as uncoated bits, 115-piece set features 29 fractional bits from 1/16-inch to 1/2-inch in increments of 1/64-inch * Cool cutting titanium nitride construction * Tough high-speed steel bits * Bits last up to six times as long as non-coated HSS bits * Bits come in a rugged indexed steel case