| 摘要 |
Two pairs of dies are arranged adjacent each other so that each pair can clamp onto a metal sheet between them. One pair is situated slightly below, or stepped down from, the other pair. One pair of dies clamps onto the sheet, and then the other pair is clamped onto it to bend the sheet so that a step is formed in the sheet between the two pairs of dies, corresponding to the step down from one pair of dies to the other. |
