Abstract: A turntable for supporting an end blank having a tubular flange integral therewith is rotatable about an axis of the tubular flange. An annular threading roll die rotatable with the turntable receives therein the flange of the end blank with a full outer circumferential surface of the tubular flange being held against the annular threading roll die. The annular threading roll die has a first inner threading surface for threading the tubular flange. A threading roll is inserted into the tubular flange of the end flange supported on the turntable in spaced relationship to an inner circumferential surface of the tubular flange. The threading roll is rotatable and movable toward the inner circumferential surface of the tubular flange, and has a second inner threading surface which is complementary to the first threading surface.
Abstract: A circular hole is defined in a top plate stock of thin sheet steel, and a peripheral edge of the circular hole is raised and radially outwardly expanded into a substantially frustoconical first flange blank. Then, a peripheral edge of a proximal portion of the first flange blank is raised and radially outwardly expanded into a substantially frustoconical second flange blank contiguous to the first flange blank, the second flange blank having a lower portion beneath the peripheral edge of the proximal portion. Finally, the third flange blank is drawn into a tubular flange which has a predetermined inside diameter and a predetermined height.
Abstract: A pipe joint has a tubular retainer for inserting pipes to be coupled therein, a joint body fitted over the retainer and having a socket holder, and a tubular socket movably disposed around the socket holder. When connecting the pipes to each other, the pipes are inserted into the retainer and positioned therein, the joint body is fitted over the retainer, and the socket holder is brought over the socket holder until the socket is held against a positioning member on the socket holder. A spring in a positioning groove in the socket holder is resiliently displaced radially outwardly partly into a smaller-diameter recess in the socket while partly remaining in the positioning groove, whereupon the socket is retained on the joint body against removal.