大(da)梁(liang)沖孔(kong)(kong)(kong)機，落料沖孔(kong)(kong)(kong)，將外形和孔(kong)(kong)(kong)一次(ci)性沖出。這些(xie)洞(dong)是(shi)(shi)工藝孔(kong)(kong)(kong)：一些(xie)是(shi)(shi)為(wei)了(le)在生產(chan)線上(shang)焊接定位孔(kong)(kong)(kong)，一些(xie)是(shi)(shi)為(wei)了(le)減重(zhong)的(de)，也(ye)有一些(xie)是(shi)(shi)過(guo)線束管路的(de)；這些(xie)正常的(de)孔(kong)(kong)(kong)都(dou)不會(hui)影響大(da)梁(liang)的(de)強(qiang)度。應力(li)孔(kong)(kong)(kong)可以釋放大(da)梁(liang)焊接產(chan)生的(de)應力(li)，增強(qiang)大(da)梁(liang)承載力(li)的(de)同時降(jiang)低自重(zhong)，拉(la)標載專用利器。