Washer-faced screws have various washers that function as springs to shorten the Place between a nut’s head plus the bolt’s head.
Put simply, a Hex head screw resembles a bolt. There's also combi head Hex head https://roryqnco048721.blogmazing.com/29113009/how-types-of-screw-heads-can-save-you-time-stress-and-money