Socket tool for forcibly detaching screw member and a method for manufacturing the socket tool

A method for manufacturing a socket tool, comprising the steps of:

• forging:
• forging and forming a socket blank which has a first end having an inner wall formed with a workpiece mounting recess having a plurality of axially arranged arcuate locking grooves, and a second end having an inner wall formed with a square mounting hole;
• hydraulic working:
• placing the socket blank between an upper mold block and a lower mold seat of a hydraulic working machine, wherein the socket blank is positioned on the lower mold seat, the upper mold block has an end face rested on the workpiece mounting recess of the socket blank and has a periphery provided with a plurality of helical mold strips matingly contacting the arcuate locking grooves of the socket blank, the upper mold block is driven and rotated by a hydraulic force of the hydraulic working machine to move toward the socket blank, and to rotate the helical mold strips, so that the arcuate locking grooves of the socket blank are twisted by the helical mold strips to matingly form a plurality of helical arcuate locking grooves, the helical mold strips have a conical shape;
• surface turning:
• turning and cutting the periphery of the socket blank to make the periphery of the socket blank smooth;
• heat treatment:
• performing a heat treatment on the socket blank to enhance the stiffness and hardness of the socket blank;
• and
• forming a product:
• forming a socket tool which has an inner wall formed with a plurality of helical arcuate locking grooves arranged in an annular manner, wherein the helical arcuate locking grooves are extended and contracted from an outer end to an inner end of the socket tool to form a contracted conical hole.