锻件是金属被施加压力，通过塑性变形塑造要求的形状或合适的压缩力的物件。这种力量典型的通过使用铁锤或压力来实现。锻件过程建造了精致的颗粒结构，并改进了金属的物理属性。Aforgedpieceisanobjectthatisappliedtothemetalbypressuretoshapetherequiredshapeortheappropriatecompressionforcebyplasticdeformation.Thisforceistypicallyachievedbyusingahammerorpressure.Theprocessofforginghasbuiltafineparticlestructureandimprovedthephysicalpropertiesofthemetal.自由锻造是靠人工操作来控制锻件的形状和尺寸的，所以锻件精度低，加工余量大，劳动强度大，生产率也不高，因此它主要应用于单件、小批量生产。Freeforgingisbymanualoperationtotheshapeandsizeoftheforgings,sotheprecisionoftheforgingsislow,theprocessingallowanceislarge,thelaborintensityisbig,andtheproductivityisnothigh.Therefore,itismainlyusedinsinglepieceand***allbatchproduction.拔长也称延伸，它是使坯料横断面积减小、长度增加的锻造工序。拔长常用于锻造杆、轴类零件。自由锻造的基本工序包括镦粗、拔长、冲孔、弯曲、扭转、错移、切割及锻接等。PullinglengthAlsoknownaselongation,itisaforgingprocesstoreducethecross-sectionalareaofthebilletandincreasethelength.Pulloutisoftenusedinforgingrodsandshaftparts.Thebasicprocessesoffreeforgingincludeupsetting,drawing,punching,bending,torsion,offset,cuttingandforging.)