機械(xie)加(jia)(jia)工(gong)(gong)是(shi)一種用(yong)(yong)加(jia)(jia)工(gong)(gong)機械(xie)對(dui)工(gong)(gong)件(jian)的(de)(de)(de)外形尺寸或性能(neng)進行(xing)改變的(de)(de)(de)過(guo)程。按被(bei)加(jia)(jia)工(gong)(gong)的(de)(de)(de)工(gong)(gong)件(jian)處于的(de)(de)(de)溫度(du)狀態﹐分為(wei)冷加(jia)(jia)工(gong)(gong)和(he)熱加(jia)(jia)工(gong)(gong)。機械(xie)加(jia)(jia)工(gong)(gong)具備(bei)著非(fei)常(chang)靈(ling)活(huo)的(de)(de)(de)制(zhi)造能(neng)力(li)，還(huan)能(neng)大批量(liang)生產，可(ke)以(yi)生產出非(fei)常(chang)精密的(de)(de)(de)機加(jia)(jia)工(gong)(gong)零(ling)件(jian)，可(ke)以(yi)在很短的(de)(de)(de)時(shi)間(jian)里面(mian)生產出完全(quan)不同的(de)(de)(de)產品。零(ling)件(jian)在加(jia)(jia)工(gong)(gong)和(he)裝配過(guo)程中所(suo)使用(yong)(yong)的(de)(de)(de)基(ji)準(zhun)，稱(cheng)為(wei)工(gong)(gong)藝基(ji)準(zhun)。工(gong)(gong)藝基(ji)準(zhun)按用(yong)(yong)途(tu)不同，又分為(wei)定位基(ji)準(zhun)、測(ce)量(liang)基(ji)準(zhun)和(he)裝配基(ji)準(zhun)。定位基(ji)準(zhun)：天津機械(xie)加(jia)(jia)工(gong)(gong)時(shi)使工(gong)(gong)件(jian)在機床或夾(jia)具中占據正(zheng)確(que)位置所(suo)用(yong)(yong)的(de)(de)(de)基(ji)準(zhun)，稱(cheng)為(wei)定位基(ji)準(zhun)。

機(ji)(ji)械(xie)加(jia)(jia)(jia)工(gong)以后的(de)零(ling)(ling)部件(jian)(jian)(jian)放在(zai)含有磨(mo)塊或者是磨(mo)劑的(de)滾筒當(dang)中，合肥機(ji)(ji)械(xie)加(jia)(jia)(jia)工(gong)，在(zai)里面(mian)(mian)(mian)(mian)會(hui)進行復雜的(de)運動，而(er)運動的(de)過程(cheng)當(dang)中會(hui)產生壓力，產生壓力會(hui)出現(xian)(xian)碰(peng)撞和滾壓，這樣(yang)就會(hui)讓(rang)(rang)零(ling)(ling)部件(jian)(jian)(jian)的(de)表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)起到(dao)輕微磨(mo)削(xue)的(de)效(xiao)果，自然也就能(neng)夠實現(xian)(xian)讓(rang)(rang)它的(de)表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)慢慢被細(xi)化，表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)也會(hui)因此變得光(guang)整很多。零(ling)(ling)部件(jian)(jian)(jian)上(shang)面(mian)(mian)(mian)(mian)有多個(ge)型(xing)腔，加(jia)(jia)(jia)工(gong)的(de)時候，不宜采(cai)用(yong)一個(ge)型(xing)腔一個(ge)型(xing)腔的(de)加(jia)(jia)(jia)工(gong)方式進行加(jia)(jia)(jia)工(gong)排列，這樣(yang)很容易造成零(ling)(ling)部件(jian)(jian)(jian)受力不均勻(yun)而(er)產生變形(xing)，大型(xing)機(ji)(ji)械(xie)加(jia)(jia)(jia)工(gong)，采(cai)用(yong)分層多次(ci)加(jia)(jia)(jia)工(gong)，每(mei)一層盡量同時加(jia)(jia)(jia)工(gong)到(dao)所(suo)有的(de)型(xing)腔，然后在(zai)加(jia)(jia)(jia)工(gong)上(shang)下一個(ge)層次(ci)，讓(rang)(rang)零(ling)(ling)件(jian)(jian)(jian)均勻(yun)受力減小(xiao)發生形(xing)變的(de)概率(lv)。對(dui)零(ling)(ling)件(jian)(jian)(jian)進行這一工(gong)序呢，一般通過精(jing)密車(che)削(xue)，研(yan)磨(mo)等操作(zuo)，常常能(neng)讓(rang)(rang)那些有色金屬材料制(zhi)作(zuo)的(de)零(ling)(ling)件(jian)(jian)(jian)表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)形(xing)成一定的(de)光(guang)潔表(biao)(biao)(biao)面(mian)(mian)(mian)(mian)，比(bi)如我們常說(shuo)的(de)鏡面(mian)(mian)(mian)(mian)效(xiao)果。

精密零(ling)(ling)部(bu)件(jian)加(jia)(jia)工(gong)的(de)定義是，按(an)(an)步驟，按(an)(an)工(gong)序完(wan)成各主要(yao)(yao)表(biao)(biao)(biao)(biao)面(mian)(mian)的(de)終加(jia)(jia)工(gong)，包括工(gong)件(jian)平行度(du)，表(biao)(biao)(biao)(biao)面(mian)(mian)光潔度(du)，表(biao)(biao)(biao)(biao)面(mian)(mian)垂直度(du)，附(fu)近(jin)機(ji)械(xie)加(jia)(jia)工(gong)廠，表(biao)(biao)(biao)(biao)面(mian)(mian)硬度(du)等(deng)(deng)等(deng)(deng)，使(shi)零(ling)(ling)件(jian)的(de)加(jia)(jia)工(gong)精度(du)和加(jia)(jia)工(gong)表(biao)(biao)(biao)(biao)面(mian)(mian)質(zhi)量達到圖樣規定的(de)要(yao)(yao)求的(de)過程。零(ling)(ling)件(jian)加(jia)(jia)工(gong)表(biao)(biao)(biao)(biao)面(mian)(mian)上，不(bu)(bu)應有(you)劃痕、擦傷等(deng)(deng)損傷零(ling)(ling)件(jian)表(biao)(biao)(biao)(biao)面(mian)(mian)的(de)缺陷，加(jia)(jia)工(gong)的(de)螺紋表(biao)(biao)(biao)(biao)面(mian)(mian)不(bu)(bu)允許有(you)黑(hei)皮(pi)、磕(ke)碰、亂(luan)扣和毛刺等(deng)(deng)缺陷。所有(you)需要(yao)(yao)進(jin)行涂(tu)裝的(de)鋼(gang)鐵(tie)制件(jian)表(biao)(biao)(biao)(biao)面(mian)(mian)在涂(tu)漆前，必須將(jiang)鐵(tie)銹、氧化皮(pi)、油脂、灰(hui)塵、泥(ni)土、鹽和污(wu)物(wu)等(deng)(deng)除去。機(ji)械(xie)加(jia)(jia)工(gong)設(she)備使(shi)用(yong)(yong)的(de)材(cai)料(liao)須符合安(an)全(quan)環保要(yao)(yao)求，不(bu)(bu)允許使(shi)用(yong)(yong)對人體有(you)害和未(wei)經安(an)全(quan)部(bu)門檢(jian)驗合格的(de)材(cai)料(liao)。