connecting wall 71 facilitates formation of the reverse bends 51 and 53 specifically the dies 75 and 77 have coining surfaces 79 and 81 respectively which coin the sheet material between reference lines a a and b b the lower coining die 75 also has horizontal supporting surfaces 83 and 85 for supporting the radial section 67 and an annular region 87 which extends between the connecting wall 71 and the dimple 73 the tooling provides spaces 88 and 88a to accommodate the elongation of the connecting wall 71 the dimple 73 is formed by a punch 89 and a cooperating die 91 the punch 89 engages the sheet material of the section 69 and offsets a zone of the same into a die cavity 93 ultimately the offset sheet material is engaged between the cooperating surfaces of the punch 89 and the die 91 to coin the sloping wall of the dimple the coined regions are generally those portions of the dimple 73 which are shown in fig9 as being compressively engaged a dimple making process which involves stretching and coining of the sheet material is disclosed in common assignee 39 s u s pat no 3 638 597.