1. to enlarge the upper part of a hole so that the head of a screw or bolt sits flush with or below the surface
Usage: present participle of countersink; common in carpentry, metalworking, and construction

1. the process or act of enlarging a hole to accommodate a screw or bolt head
Usage: gerund form; refers to the technique or action itself

Examples

• The carpenter is countersinking the screws so they won't stick out.
• Countersinking requires a special drill bit designed for the task.
• After drilling the pilot hole, countersinking ensures a smooth, finished appearance.
• The technician finished countersinking all the bolts on the metal frame.
• Proper countersinking prevents screws from catching on clothing or skin.
• She practiced countersinking on scrap wood before working on the final project.