機(ji)械加(jia)(jia)(jia)工(gong)是指通過(guo)一種機(ji)械設備對工(gong)件(jian)的外形(xing)尺寸(cun)或性能(neng)進行改變的過(guo)程。按加(jia)(jia)(jia)工(gong)方式上的差別(bie)可分為切削加(jia)(jia)(jia)工(gong)和壓力加(jia)(jia)(jia)工(gong)。

在生產(chan)(chan)過(guo)程(cheng)中，凡是(shi)改變生產(chan)(chan)對象的形(xing)狀(zhuang)、尺(chi)寸(cun)、位置和性質等(deng)(deng)，使其(qi)成為成品或(huo)者半成品的過(guo)程(cheng)稱為工(gong)(gong)藝(yi)(yi)過(guo)程(cheng)。它是(shi)生產(chan)(chan)過(guo)程(cheng)的主要部分。工(gong)(gong)藝(yi)(yi)過(guo)程(cheng)又可分為鑄造、鍛(duan)造、沖壓、焊接、機(ji)械加工(gong)(gong)、裝配(pei)等(deng)(deng)工(gong)(gong)藝(yi)(yi)過(guo)程(cheng)，機(ji)械制造工(gong)(gong)藝(yi)(yi)過(guo)程(cheng)一(yi)般是(shi)指零件的機(ji)械加工(gong)(gong)工(gong)(gong)藝(yi)(yi)過(guo)程(cheng)和機(ji)器的裝配(pei)工(gong)(gong)藝(yi)(yi)過(guo)程(cheng)的總和，其(qi)他(ta)過(guo)程(cheng)則稱為輔(fu)助過(guo)程(cheng)，例如運輸(shu)、保管、動力(li)供應、設備(bei)維修等(deng)(deng)。工(gong)(gong)藝(yi)(yi)過(guo)程(cheng)又是(shi)由一(yi)個(ge)(ge)或(huo)若(ruo)干個(ge)(ge)順序(xu)排列的工(gong)(gong)序(xu)組成的，一(yi)個(ge)(ge)工(gong)(gong)序(xu)由有(you)若(ruo)干個(ge)(ge)工(gong)(gong)步組成。