phillips head screws came into use in 1935.
phillips head screws came into use in 1935.
when did phillips head screws come into use?
1935
Na
Na
by design, torx head screws resist cam-out better than phillips head or slot head screws. whereas the tendency of phillips drivers to cam out under excessive torque has been listed as a feature preventing damage to the screw-head or driver, torx heads were designed to "prevent" cam-out. the development of better torque-limiting automatic screwdrivers for use in factories allowed this change. rather than rely on the tool to slip out of the screw head when a desired torque level is reached (which risks damage to the driver tip, screw head, and/or workpiece), torque-limiting driver designs achieve a desired torque consistently.
torx