在鍛造時，金屬的脆性雜質被打碎 ，順著金屬主要伸長方向呈碎粒狀或鏈狀分布；塑性雜質隨著金屬變形沿主要伸長方向呈帶狀分布 ， 這樣熱鍛后的金屬組織就具有一定的方向性。

When forging, the brittle metal impurities to be broken down, the main direction of elongation is like particles of metal or plastic chain distribution; impurities with metal deformation distributed along the main direction of elongation, so after hot forging metal organization has certain direction.

自由鍛生產率低，加工余量大，但工具簡單，通用性大，故被廣泛用于鍛造形狀較簡單的單件、小批生產的鍛件。自由鍛設備有空氣錘、蒸汽-空氣錘和水壓機等，分別適合小、中和大型鍛件的生產。

Free forging has many advantages such as low productivity, large machining allowance, but simple tool and versatility. So it is widely used for forging single piece and small batch forgings with simpler shape. The free forging equipments include air hammer, steam air hammer and hydraulic press, etc., which are suitable for the production of small and medium heavy forgings, respectively.

自由鍛造所用工具和設備簡單，通用性好，成本低。 同鑄造毛坯相比，自由鍛消除了縮孔、 縮松、氣孔等缺陷，使毛坯具有更高的力學性能。鍛件形狀簡單，操作靈活。

Free forging tools and equipment are simple, versatility and low cost. Compared with the casting blank, the free forging eliminates the defects such as shrinkage porosity, porosity, porosity and so on, so that the blank has higher mechanical properties. The shape of the forgings is simple and the operation is flexible.