In the thirties , the automobile industry was beginning to boom out , and car were being produced on an assembly line using automated power tools . Henry Phillips of the Phillips Screw Company in Portland , Ore. , excogitate a screw that would take more torque than the usual ass with its undivided expansion slot , on which the screwdriver would be easily concentrate on and would be less potential to slew . He consider his newly designed shag , with its cross - shaped expansion slot and its young screwdriver , would avail better the efficiency of the machine assembly ancestry , allowing part to be cheat into place well and efficiently . It take longer than Phillips expect for the auto industry to capture on , but eventually he was proven right , and today the Phillips screwing and screwdriver are common all over the world .
One of the chief reward of the Phillips system is that the screw and screwdriver together are ego - centering . The x - configuration of the screwdriver head fits into the likewise shaped slot of the screw and is held in spot so the power of the torsion is course rivet , ensuring that the screw is driven straight . By comparison , with a regular , exclusive - slot fucking , the screwdriver can easily slip out of the center ( and sometimes , out of the screw wholly ) induce the screw to ride at an slant . A further advantage is that once the shtup has reached its maximal torque , the screw number one wood " cams out " : It pops out of the screw so the turnkey ca n’t be overdrive , and the sides of the time slot are n’t damaged . It ’s not clear whether this was mean by design , but it ’s a helpful feature of speech .
Henry Phillips patented his screwdriver and screw , and the engineering related to them in 1936 . However , the Phillips tool became so ubiquitous that in 1949 he lose the patent , although his name has remained linked to both the screwdriver and the screw .
