The punch includes an end portion adapted to Pierce an entry hole and bend material around the entry hole to form a retained slug along an inner edge of the entry hole.
该冲头包括端部，该端部适于刺穿入口孔并折弯环绕该入口孔的材料，以沿着该入口孔的内缘形成残留的废料。
2
The quality of the internal surface can be greatly improved and the punch force can be significantly reduced by using inner set hose.
内置软管可以有效改善管材的内表面质量，并显著减小冲头推力。
3
But, Young says, when one worker is greeted with a polite how-do-you-do while the guy next door gets a playful pretend-punch, it's clear in an instant who is in the inner circle and who isn't.