Looduslik vormimismeetod: looduslikku vormimismeetodit nimetatakse ka rullvormimismeetodiks (CFE). Selle vormimismeetodi omadused seisnevad selles, et vormimisprotsessis konfigureeritakse rulligrupp piki vertikaalset sidumisserva, et juhtida serva pikendust. Samal ajal on rullirühmad väljastpoolt vaoshoitud.
Extend the edge as a compressed deformation form to absorb, so that the forming process of the tanded steel is close to the forming method of natural bending shape. Therefore, it is a forming method that can prevent the edge extension and absorb marginal extension, which is suitable for the inhabitant medium -caliber thin wall tube (D>400 mm).
