5/16-Inch Magnetic Hex Head Driver Bit w/Quick Change Shank - Used for Installing Screws, Nuts, Bolts, etc. - Commonly Used for Metal Roofing Screws (EACH) - Amazon.com
4-40 × 5/16" Screw for Bit Holder Track - Lee Valley Tools
5/16" Screw Machine Length Drill Bit 135° pt. - 6 per Pack | K.L. Jack
Pan American Tool 28-715 Steel 5/16" Style PAT-212-5/16A 1-1/4" Long Torq-Set Screw Insert Bit at SkyGeek.com