Inventors:
Randall L. Alexoff - Youngstown OH
Assignee:
George A. Mitchell Company - Youngstown OH
International Classification:
B21C 124
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.