Phillips pan head machine screw, 1 x 30. Designed to go through a pre-tapped hole or nut to form a mating thread for the screw. Has a general purpose bearing area and can be substituted in most applications for round, truss, or binding heads. Phillips drive is the most common drive used and is designed to "camout" when the screw reaches optimum tightness, thus preventing damage to the screw head.