The mold generally includes two parts, a movable mold and a fixed mold (or a punch and a concave mold), which can be divided and closed. The mold is a precision mold with complex shape, which bears the expansion force of the blank, and has high requirements on structural strength, rigidity, surface hardness, surface roughness and machining accuracy. The development level of mold production is one of the important signs of the level of machinery manufacturing.
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