Fig. 14 indicates a six-sided flange nut. These are useful to obtain a large bearing for the nut's face, without using a heavy nut. And if contact with angles or corners is to be avoided, the flange is curved as in Fig. 17, which denotes a handsome nut, well adapted to bear upon brass or gun metal, or other soft metal, without wearing or tearing the surfaces in contact. The forging of flange nuts is performed by forcing the iron while at a welding heat into top and bottom tools, which are made to the required shape. Each nut is punched and cut from the bar and afterwards heated to welding, and then compressed to shape by striking the top-tool Avhile the nut is on a mandril held by the workman. The mandrils for welding and shaping the outsides of nuts need not to be turned by a lathe, because the opening in each nut is afterwards shaped and finished by a finishing mandril specially made for the purpose (Fig. 96).