機械加工(gong)(gong)是指通過一種機械設備對工(gong)(gong)件的外形尺寸(cun)或性能進行(xing)改變的過程。按加工(gong)(gong)方式上的差別可分為切削加工(gong)(gong)和壓力加工(gong)(gong)。

在生產過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)中，凡是(shi)改變生產對象(xiang)的形(xing)狀(zhuang)、尺寸、位置和(he)性質等(deng)，使其成為(wei)成品或(huo)者半成品的過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)稱為(wei)工(gong)(gong)藝(yi)(yi)過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)。它(ta)是(shi)生產過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)的主要(yao)部分。工(gong)(gong)藝(yi)(yi)過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)又可分為(wei)鑄造、鍛(duan)造、沖(chong)壓、焊(han)接、機(ji)(ji)械加(jia)(jia)工(gong)(gong)、裝配等(deng)工(gong)(gong)藝(yi)(yi)過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)，機(ji)(ji)械制造工(gong)(gong)藝(yi)(yi)過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)一(yi)般(ban)是(shi)指零件的機(ji)(ji)械加(jia)(jia)工(gong)(gong)工(gong)(gong)藝(yi)(yi)過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)和(he)機(ji)(ji)器的裝配工(gong)(gong)藝(yi)(yi)過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)的總和(he)，其他(ta)過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)則(ze)稱為(wei)輔助過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)，例如(ru)運輸、保(bao)管、動力供應、設備維修等(deng)。工(gong)(gong)藝(yi)(yi)過(guo)(guo)程(cheng)(cheng)(cheng)(cheng)又是(shi)由一(yi)個(ge)或(huo)若干個(ge)順(shun)序(xu)(xu)排列的工(gong)(gong)序(xu)(xu)組成的，一(yi)個(ge)工(gong)(gong)序(xu)(xu)由有若干個(ge)工(gong)(gong)步組成。