Machine screws have a uniform diameter along their entire length and are designed to screw into threaded holes or to be used in combination with machine screw hex nuts. They are frequently used in machinery and appliances. These machine screws feature a tamper resistant one-way head and require a special tool to remove (alternatively a slot can be cut into the head that would allow removal with a flat head screw driver). Install using flat head screw driver or one-way screw slotted driver bit.