Hitachi 728335B25 1-Inch Philips No.1 Driver Bits, 25-Pack  (Discontinued by the Manufacturer) (Discontinued by the Manufacturer) Treated first with a heat treating process and then with DuraCore, Hitachi driver bits are stronger and more durable than other driver bits Hitachi DuraCore treated products are manufactured utilizing a proprietary technologically superior to cryogenic treatment Hitachi driver bits come in various lengths and head tips for any application These Philips No.1 bits are ideal for contractors, serious do-it-yourselfers, machine shops, and mechanics Comes with a 30-day limited warranty