Abstract: A method and apparatus for draw forming, from a tubular workpiece, a tube or hollow shaft having a variable wall thickness, using a reducing die without an internal mandrel. A tension force is applied to the workpiece at one axial side of the die and a compression force is applied at the opposite axial side of the die. Changing the relative magnitudes of the tensile and compressive forces produces corresponding changes in the wall thickness as the workpiece passes through the die.

Abstract: A method and apparatus for producing an end connection by which a tube of variable wall thickness can be formed by being drawn between a die and a mandrel. The end of tubular stock is reduced and its wall thickness increased by being extruded into the space between a reducing die and a mandrel located within the tube, the mandrel having a plug that forms the inner surface of the formed tube as the mandrel and die are retraced from the end. A screw thread is formed on the inner surface of the formed tube and is engaged by a screw thread on a pull pin adapted for attachment to an actuating cylinder that applies a force tending to pull the tube through the die and mandrel.

Abstract: Method for severing the ends of tubing by feeding the end of a tube through a die such that its end to be sheared extends beyond the die while presenting a shear blade with a pointed end in the interior of the tube end. After the shear blade is inserted into the tube, relative vertical movement between the shear blade and the tube is effected to cause the pointed end to initially puncture the tube wall adjacent the die. The shearing blade is thereafter shifted laterally and vertically to shear remaining portions of the tube wall.

Abstract: A method for producing tubing of variable wall thickness, and particularly for producing double-butted tubing, wherein the wall thickness or gage at the ends of the tube is greater than that in the intermediate portion of the tube. This is accomplished by threading the tube over a mandrel, usually having a removable plug at one end thereof, until a portion of the plug passes through a necked-down end of the tube, pushing the tube and the mandrel through a die, and thereafter pulling the removable plug and the tube from the mandrel while causing the outer periphery of the tube to pass through a die.