Cheese head screws are a common type of screw that have a rounded top and a cylindrical base. They are often used in applications where a flush finish is not required and where the head of the screw needs to be easily accessible for adjustment or removal. Also, Phillips, square, hex and Torx® drive screws are popular because there's less chance for the driver to slip out and scratch finish work. Hex head, like hex cap screws, require a wrench or socket. Use a wrench for square head bolts and screws.