自由鍛造時，被加工金屬在上、下砧鐵之間受壓產生變形，在水平面的各個方向金屬能自由流動，故稱自由鍛造。

 自(zi)由鍛(duan)(duan)(duan)造(zao)所(suo)(suo)用設備(bei)和工(gong)(gong)(gong)具(ju)通用性較(jiao)大，鍛(duan)(duan)(duan)件(jian)的(de)質量大小不(bu)等(deng)。但(dan)是，自(zi)由鍛(duan)(duan)(duan)件(jian)的(de)形狀和尺寸主要(yao)(yao)依靠鍛(duan)(duan)(duan)工(gong)(gong)(gong)的(de)操作(zuo)技術來保證(zheng)，對(dui)鍛(duan)(duan)(duan)工(gong)(gong)(gong)的(de)技術水(shui)平要(yao)(yao)求高(gao)，勞動強(qiang)度(du)大，生(sheng)產率低，鍛(duan)(duan)(duan)件(jian)的(de)精度(du)低，加工(gong)(gong)(gong)余量大，且不(bu)能獲(huo)得較(jiao)復雜(za)的(de)形狀。所(suo)(suo)以(yi)主要(yao)(yao)用于單件(jian)、小批生(sheng)產以(yi)及修配工(gong)(gong)(gong)作(zuo)。對(dui)于大型(xing)鍛(duan)(duan)(duan)件(jian)，自(zi)由鍛(duan)(duan)(duan)造(zao)是唯一的(de)生(sheng)產方法。自(zi)由鍛(duan)(duan)(duan)造(zao)有手(shou)工(gong)(gong)(gong)鍛(duan)(duan)(duan)和機器鍛(duan)(duan)(duan)兩種。

 手工(gong)(gong)鍛(duan)是靠人力(li)利用(yong)砧鐵、大(da)錘(chui)、小錘(chui)、手鉗(qian)、沖子、鑿子和型(xing)錘(chui)等工(gong)(gong)具(ju)(ju)，使坯料變(bian)形(xing)制(zhi)成鍛(duan)件的(de)(de)加工(gong)(gong)方法。手工(gong)(gong)鍛(duan)所用(yong)的(de)(de)設備和工(gong)(gong)具(ju)(ju)簡單、投資少，但勞動強度大(da)、生產率(lv)低，適用(yong)于修理工(gong)(gong)作(zuo)以及機(ji)器鍛(duan)的(de)(de)輔助工(gong)(gong)作(zuo)。

 手工(gong)(gong)鍛是由(you)掌鉗工(gong)(gong)和(he)打錘(chui)(chui)(chui)工(gong)(gong)配(pei)合進(jin)行操作的(de)(de)。掌鉗工(gong)(gong)左手握(wo)鉗，用以夾持、移(yi)動和(he)翻轉工(gong)(gong)件；右手握(wo)小錘(chui)(chui)(chui)，用于變形(xing)量很小的(de)(de)鍛打和(he)指(zhi)揮錘(chui)(chui)(chui)工(gong)(gong)的(de)(de)操作。打錘(chui)(chui)(chui)工(gong)(gong)雙手握(wo)大錘(chui)(chui)(chui)，站在砧鐵的(de)(de)外(wai)側進(jin)行錘(chui)(chui)(chui)擊(ji)。

 機器(qi)(qi)鍛是利用機器(qi)(qi)產(chan)生(sheng)(sheng)的(de)沖擊(ji)力或壓力使坯(pi)料變(bian)形的(de)加(jia)工(gong)方法(fa)。它的(de)生(sheng)(sheng)產(chan)率較高，但仍是自由鍛造的(de)基本(ben)方法(fa)。

 機(ji)(ji)器鍛造所用的設備(bei)有空氣錘、蒸(zheng)汽錘和水(shui)壓(ya)機(ji)(ji)等，其中以空氣錘應(ying)用最為廣(guang)泛。它(ta)有壓(ya)縮(suo)汽缸和工(gong)(gong)作(zuo)汽缸，壓(ya)縮(suo)汽缸內有壓(ya)縮(suo)活塞(sai)(sai)，由電動機(ji)(ji)經減速(su)機(ji)(ji)構再借曲柄－連桿機(ji)(ji)構帶(dai)動而作(zuo)上(shang)下(xia)運動。當(dang)壓(ya)縮(suo)活塞(sai)(sai)上(shang)升(sheng)時，將(jiang)空氣壓(ya)人工(gong)(gong)作(zuo)汽缸的上(shang)部，使工(gong)(gong)作(zuo)活塞(sai)(sai)連同錘頭和上(shang)砧鐵下(xia)擊。當(dang)壓(ya)縮(suo)活塞(sai)(sai)下(xia)降時，將(jiang)空氣壓(ya)人工(gong)(gong)作(zuo)汽缸的下(xia)部，使工(gong)(gong)作(zuo)活塞(sai)(sai)連同錘頭上(shang)升(sheng)。