圆拉模在拉伸圆钢时,孔径将逐渐增大,当超过允许公差时,这个拉模就只好报废。这不仅造成很大的经济损失,也往往引起生产工序的不平衡。怎么才能使这种废拉模复用,即如何使增大的孔径又缩小到允许的公差范围内呢?对此,我厂进行了缩孔处理的初步试验,并已在生产中运用,效 Circular dies in the stretch bar, the aperture will gradually increase, when the allowable tolerance exceeded, the draft had to scrapped. This not only causes great economic losses, but also often leads to an imbalance in the production process. How to make this waste die reuse, that is, how to make the increase of the aperture and reduced to the allowable tolerance? In this regard, I conducted a preliminary plant shrinkage treatment, and has been used in the production, efficiency