Nut integrated with bracket and method of manufacturing the same

A method of manufacturing a nut integrated with a bracket, the method comprising:

• a pre-drawing step of forming a reference hole and a processing cross section in a plate material supplied between a punch and a die, forming a beading portion by processing the processing cross section through multiple steps, and piercing a center of the beading portion to form a through hole;
• a forging step of forming a pipe portion having a tube shape by gradually widening the through hole in the beading portion and decreasing an inner diameter and an outer diameter of the pipe portion from the processing cross section to a tip of the beading portion, and then processing an outer circumferential surface of the pipe portion so as to form the tube shape through multiple steps so that a thickness is increased from the tip of the pipe portion to the processing cross section, subsequent to the pre-drawing step;
• a precision forging step of precisely correcting dimensions of the inner diameter and the outer diameter of the pipe portion formed in the tube shape, and forming a protruding end from the tip of the pipe portion, subsequent to the forging step;
• and
• a post-processing step of cutting the processing cross section to a final product shape, forming bent ends at both end portions of the cut processing cross section, and forming a threaded tap on an inner circumferential surface of the pipe portion, subsequent to the precision forging step,
• wherein the precision forging step includes:
• an upsetting step of precisely correcting the dimensions of the inner diameter and the outer diameter of the pipe portion by compressing the pipe portion, which is formed in the tube shape, in a longitudinal direction through multiple steps, subsequent to the forging step;
• a cam upsetting step of forming an increased thickness portion, which protrudes at an outer circumference of the tip of the pipe portion, and further forming the protruding end which protrudes in a longitudinal direction from a tip surface of the increased thickness portion, by compressing the inner and outer circumferential surfaces and a tip portion of the pipe portion, which have the corrected dimensions, to predetermined shapes, subsequent to the upsetting step;
• and
• a cam rest burring step of removing residual burrs on the pipe portion by compressing the inner and outer circumferential surfaces and the tip portion of the pipe portion, which has the increased thickness portion and the protruding end, to predetermined shapes, subsequent to the cam upsetting step.