Aviation Dictionary
سکه زنی با ماشین مخصوص ،ایجاد فرو رفتگی روی فلزات، خزینه سازی
A process of preparing holes in sheet metal to receive flush rivets. the metal in the area to be dimpled is heated, and a coining die is pressed into it. the pressure of the die in the softened metal gives the dimpled hole sharp edges that provide a good fit for the countersunk rivet heads.