History of Square & Phillips screw drivers

History of Square & Phillips screw drivers slot robertson screw Phillips screwdrivers; Torx screwdrivers; Hex screwdrivers; Robertson screwdrivers Flathead screwdrivers are used for screws with a single slot, while Phillips slot 383 This zinc-plated, round head machine screw has a squareslot drive and a size two driver It is 8-32 x 1 12 inches and available in a box of 100 Technical

slot 383 The square-head screw was invented by P I Robertson, a Canadian, in 1908 It offered a big advantage over the slotted screw head because

slot analyse Square drive & Phillips screw with Lube finish Lo-Root Features Type 17 shank slot cuts into material  In 1908, Canadian Peter Robertson invented a square-head screw drive where the driver and the hole had a slight taper There had been other