Wilson, Failure of certain Cast Steel Dies. 





r^-^T 



T.i-S- 



FIC.I 



The dies, one of which is shewn in section in Fig. i, 

 are sections of a right cylinder cut off by parallel plane 

 faces perpendicular to the axis, and having an axial 

 circular aperture passing from one face to the other and 

 diminishing in radius at the same time. The aperture is 

 shown at EFGH, the tangents to the curves at /^anrl H 

 being parallel to OX. The initial diameter of the aper- 

 ture is usually greater than that of the tube, whilst the 

 final diameters of tube and aperture are the same. 



