These corrosion-resistant screws have sharp external teeth that hold better than screws with internal teeth when vibration resistance matters. They’re less likely to come loose during vibration, but the teeth may snag on surrounding objects. Also known as Sems screws, the washer rotates freely but is permanently attached. They have a moderate height and width profile, offering a middle ground between narrower button heads and wider truss heads. The Phillips drive easily aligns with drivers and withstands more torque than slotted drives, but drivers slip when you apply too much force.

Length is measured from under the head.