Machine elements are elementary mechanical parts used as building blocks for the construction of most device ,apparatus,and machinery.

when cutting materials have a hard,or abrasive surface,conventional milling allows the tooth of the cutter to come up underneath the crust and shear the hard chip off the work surface.

Forging means the shaping of metal by a series of hammer blows,or by slow application of pressure.

机械零件是基本的机械部件,是构筑多数设备、用具和机械的积木。当切削材料具有坚硬或耐磨的表面，传统铣削可以使刀具的齿部由硬皮下方伸出进而将硬皮剪除工作面。
锻造是通过一系列的锤冲击，或缓慢加压作用使得金属成型。