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。

 自由(you)(you)鍛(duan)(duan)(duan)造所用(yong)設備和工(gong)(gong)具通用(yong)性較大，鍛(duan)(duan)(duan)件(jian)的質量(liang)大小不等。但是(shi)(shi)，自由(you)(you)鍛(duan)(duan)(duan)件(jian)的形狀(zhuang)和尺寸主要依靠鍛(duan)(duan)(duan)工(gong)(gong)的操作技(ji)術來保(bao)證，對(dui)鍛(duan)(duan)(duan)工(gong)(gong)的技(ji)術水平要求高，勞動強度大，生產(chan)率低(di)，鍛(duan)(duan)(duan)件(jian)的精(jing)度低(di)，加工(gong)(gong)余(yu)量(liang)大，且不能獲得(de)較復雜的形狀(zhuang)。所以主要用(yong)于(yu)(yu)單件(jian)、小批生產(chan)以及修配(pei)工(gong)(gong)作。對(dui)于(yu)(yu)大型鍛(duan)(duan)(duan)件(jian)，自由(you)(you)鍛(duan)(duan)(duan)造是(shi)(shi)唯一的生產(chan)方法。自由(you)(you)鍛(duan)(duan)(duan)造有手工(gong)(gong)鍛(duan)(duan)(duan)和機器鍛(duan)(duan)(duan)兩種。

 手(shou)工(gong)(gong)鍛(duan)(duan)(duan)是(shi)靠人力(li)利用(yong)砧鐵、大(da)錘(chui)、小(xiao)錘(chui)、手(shou)鉗(qian)、沖子(zi)、鑿子(zi)和(he)型錘(chui)等工(gong)(gong)具，使(shi)坯料變形制成鍛(duan)(duan)(duan)件的(de)加工(gong)(gong)方(fang)法。手(shou)工(gong)(gong)鍛(duan)(duan)(duan)所(suo)用(yong)的(de)設備和(he)工(gong)(gong)具簡單、投資少，但勞動(dong)強(qiang)度大(da)、生產率低，適用(yong)于修理工(gong)(gong)作(zuo)以及機器(qi)鍛(duan)(duan)(duan)的(de)輔助(zhu)工(gong)(gong)作(zuo)。

 手工(gong)(gong)鍛是由掌鉗(qian)(qian)工(gong)(gong)和(he)打(da)錘(chui)工(gong)(gong)配合進行操作的。掌鉗(qian)(qian)工(gong)(gong)左手握(wo)鉗(qian)(qian)，用(yong)以夾持、移動和(he)翻(fan)轉工(gong)(gong)件；右手握(wo)小錘(chui)，用(yong)于變形量很(hen)小的鍛打(da)和(he)指揮錘(chui)工(gong)(gong)的操作。打(da)錘(chui)工(gong)(gong)雙(shuang)手握(wo)大錘(chui)，站在砧鐵的外(wai)側進行錘(chui)擊。

 機器(qi)鍛是(shi)利(li)用機器(qi)產生(sheng)的沖擊力或壓力使坯料變形(xing)的加(jia)工(gong)方法(fa)(fa)。它的生(sheng)產率較高，但仍是(shi)自(zi)由鍛造的基本方法(fa)(fa)。

 機(ji)(ji)器鍛造(zao)所用的(de)(de)設備有空氣(qi)(qi)錘(chui)、蒸汽(qi)(qi)(qi)錘(chui)和(he)水壓(ya)(ya)(ya)機(ji)(ji)等，其中(zhong)以空氣(qi)(qi)錘(chui)應用最為廣泛。它(ta)有壓(ya)(ya)(ya)縮汽(qi)(qi)(qi)缸和(he)工(gong)(gong)作(zuo)汽(qi)(qi)(qi)缸，壓(ya)(ya)(ya)縮汽(qi)(qi)(qi)缸內有壓(ya)(ya)(ya)縮活(huo)(huo)(huo)塞，由電動(dong)機(ji)(ji)經減速(su)機(ji)(ji)構(gou)再借(jie)曲柄－連桿機(ji)(ji)構(gou)帶動(dong)而作(zuo)上(shang)下運(yun)動(dong)。當(dang)壓(ya)(ya)(ya)縮活(huo)(huo)(huo)塞上(shang)升時(shi)，將空氣(qi)(qi)壓(ya)(ya)(ya)人工(gong)(gong)作(zuo)汽(qi)(qi)(qi)缸的(de)(de)上(shang)部，使工(gong)(gong)作(zuo)活(huo)(huo)(huo)塞連同錘(chui)頭(tou)和(he)上(shang)砧鐵下擊。當(dang)壓(ya)(ya)(ya)縮活(huo)(huo)(huo)塞下降時(shi)，將空氣(qi)(qi)壓(ya)(ya)(ya)人工(gong)(gong)作(zuo)汽(qi)(qi)(qi)缸的(de)(de)下部，使工(gong)(gong)作(zuo)活(huo)(huo)(huo)塞連同錘(chui)頭(tou)上(shang)升。