Irwin Tools  1840316 19-Piece Impact Series Drill/Drive Set Built for maximum durability and long life when used with an impact driver Forged square and Phillips bits for superior fitment, reducing stripping and increasing bit life Manufactured with heavy-duty, cold-forged, high-grade steel to withstand high-torque output Black oxide finish on the impact driver bits resists corrosion and increases the life of each bit 1-piece construction drill bits withstand high-torque loads