Magnetic Nutsetter, 5/16" Hex Lobular, 1/4" Hex Shank with Groove, 1-7/8" Long, Bulk, 3 per Bag For use with sheet metal screws and other hexagonal head fasteners. Best suited for maintenance and repair work. Lobular design reduces stripping damage by driving the fastener on the sides instead of forcing the corners to turn. For use with sheet metal screws and other hexagonal head fasteners. Provides more clearance on the corners of the fastener where paint build-up can occur.