플랫 카운터 싱크 헤드 도난 방지 보안 나사

Slot screw drives have a single horizontal indentation (the slot) in the fastener head and is driven by a "common blade" or flat-bladed screwdriver. This form was the first type of screw drive to be developed, and for centuries, it was the simplest and cheapest to make. slot head screw...