| 摘要 |
The disclosure deals with a method of producing round lids with thread-engagement lugs. A round workpiece of rolled sheet metal is deep drawn to form a cup-shaped lid blank with a depending edge portion and during the deep drawing operation the depending edge portion is stamped with spaced finger grips. The finger grips are, seen from the center point of the round workpiece, stamped in four major directions which lie in the rolling direction of the rolled sheet metal and at right angles thereto. The lower edge of the stamped edge portion is then bent to form the finished lid and its thread-engagement lugs. |
