精(jing)(jing)密零部(bu)件加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)的(de)(de)定義(yi)是，按(an)步驟(zou)，按(an)工(gong)(gong)(gong)(gong)(gong)(gong)序完成各主(zhu)要(yao)表(biao)(biao)面(mian)的(de)(de)終加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)，包括(kuo)工(gong)(gong)(gong)(gong)(gong)(gong)件平行度(du)，表(biao)(biao)面(mian)光潔度(du)，表(biao)(biao)面(mian)垂直度(du)，表(biao)(biao)面(mian)硬(ying)度(du)等(deng)等(deng)，使(shi)零件的(de)(de)加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)精(jing)(jing)度(du)和加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)表(biao)(biao)面(mian)質(zhi)量達到圖樣規定的(de)(de)要(yao)求的(de)(de)過程(cheng)。機(ji)械加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)性(xing)能不(bu)僅和企業(ye)的(de)(de)利益(yi)相關，還和安(an)(an)全(quan)性(xing)相關，在(zai)給企業(ye)帶(dai)來經濟效(xiao)益(yi)的(de)(de)同(tong)時，大型機(ji)械加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)廠，還可(ke)以(yi)有效(xiao)降低安(an)(an)全(quan)事故發(fa)生(sheng)的(de)(de)概率(lv)。機(ji)械加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)是一種用加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)機(ji)械對工(gong)(gong)(gong)(gong)(gong)(gong)件的(de)(de)外形尺(chi)寸(cun)或性(xing)能進行改變的(de)(de)過程(cheng)。按(an)被加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)的(de)(de)工(gong)(gong)(gong)(gong)(gong)(gong)件處(chu)于的(de)(de)溫度(du)狀(zhuang)態﹐分為冷(leng)加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)和熱加(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)。

由毛坯變成(cheng)成(cheng)品的(de)(de)(de)過程中，在某加(jia)(jia)工(gong)表面上(shang)切除(chu)的(de)(de)(de)金屬層(ceng)的(de)(de)(de)總(zong)厚度(du)稱為(wei)該表面的(de)(de)(de)加(jia)(jia)工(gong)總(zong)余(yu)量(liang)。每一(yi)(yi)(yi)(yi)道工(gong)序所(suo)切除(chu)的(de)(de)(de)金屬層(ceng)厚度(du)稱為(wei)工(gong)序間加(jia)(jia)工(gong)余(yu)量(liang)。機械零(ling)件是由若(ruo)干個表面組成(cheng)的(de)(de)(de)，研究零(ling)件表面的(de)(de)(de)相對關系，必須確定一(yi)(yi)(yi)(yi)個基準(zhun)，黃(huang)山機械加(jia)(jia)工(gong)，基準(zhun)是零(ling)件上(shang)用來(lai)確定其(qi)它點(dian)、線、面的(de)(de)(de)位置所(suo)依據(ju)的(de)(de)(de)點(dian)、線、面。根(gen)據(ju)基準(zhun)的(de)(de)(de)不同(tong)功能，基準(zhun)可分為(wei)設計基準(zhun)和(he)(he)工(gong)藝(yi)基準(zhun)兩(liang)類。精密(mi)和(he)(he)超精密(mi)加(jia)(jia)工(gong)時現(xian)代(dai)機械加(jia)(jia)工(gong)制(zhi)造技術的(de)(de)(de)一(yi)(yi)(yi)(yi)個重(zhong)要組成(cheng)部分，是衡量(liang)一(yi)(yi)(yi)(yi)個國家高(gao)科(ke)技制(zhi)造業(ye)水平高(gao)低的(de)(de)(de)重(zhong)要指(zhi)標之一(yi)(yi)(yi)(yi)。

機(ji)械(xie)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)的(de)(de)(de)(de)處(chu)(chu)理(li)辦法有熱(re)(re)處(chu)(chu)理(li)。熱(re)(re)處(chu)(chu)理(li)工(gong)(gong)(gong)(gong)(gong)(gong)序的(de)(de)(de)(de)安(an)排是(shi)為了(le)(le)提(ti)高(gao)金屬的(de)(de)(de)(de)切削性(xing)能，通常在(zai)(zai)機(ji)械(xie)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)前進行。為了(le)(le)消除內(nei)應力，一(yi)(yi)般在(zai)(zai)粗(cu)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)之(zhi)后(hou)(hou)，精(jing)(jing)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)之(zhi)前進行。為了(le)(le)提(ti)高(gao)零件的(de)(de)(de)(de)機(ji)械(xie)性(xing)能，滲碳(tan)、淬火、回火等(deng)，大型機(ji)械(xie)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)廠家，一(yi)(yi)般經(jing)過機(ji)械(xie)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)后(hou)(hou)才進行。零部件上面有多(duo)(duo)個(ge)(ge)(ge)(ge)型腔(qiang)，加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)的(de)(de)(de)(de)時候(hou)，不(bu)宜采(cai)用一(yi)(yi)個(ge)(ge)(ge)(ge)型腔(qiang)一(yi)(yi)個(ge)(ge)(ge)(ge)型腔(qiang)的(de)(de)(de)(de)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)方式進行加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)排列，這樣很容易造成零部件受力不(bu)均勻而產生(sheng)變(bian)形，采(cai)用分層(ceng)(ceng)多(duo)(duo)次加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)，數控(kong)機(ji)械(xie)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)中(zhong)心，每一(yi)(yi)層(ceng)(ceng)盡量同(tong)時加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)到(dao)所(suo)有的(de)(de)(de)(de)型腔(qiang)，然后(hou)(hou)在(zai)(zai)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)上下一(yi)(yi)個(ge)(ge)(ge)(ge)層(ceng)(ceng)次，讓零件均勻受力減小發生(sheng)形變(bian)的(de)(de)(de)(de)概率。精(jing)(jing)密(mi)零件加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)其實是(shi)機(ji)械(xie)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)的(de)(de)(de)(de)一(yi)(yi)種，但是(shi)因(yin)為對(dui)零件的(de)(de)(de)(de)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)精(jing)(jing)密(mi)度較高(gao)，對(dui)生(sheng)產機(ji)械(xie)及流程要求(qiu)也比較高(gao)。隨著工(gong)(gong)(gong)(gong)(gong)(gong)業化發展，精(jing)(jing)密(mi)機(ji)械(xie)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)分類越(yue)來(lai)越(yue)多(duo)(duo)，方向(xiang)越(yue)來(lai)越(yue)細，越(yue)來(lai)越(yue)化。