DICT.TW Dictionary Taiwan

 Coun·ter·sink, n.
 1. An enlargement of the upper part of a hole, forming a cavity or depression for receiving the head of a screw or bolt.
 Note: ☞ In the United States a flaring cavity formed by chamfering the edges of a round hole is called a countersink, while a cylindrical flat-bottomed enlargement of the mouth of the hole is usually called a conterbore.
 2. A drill or cutting tool for countersinking holes.
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