Abstract: A driving rod assembly includes a rod having an insertion section for coupling with a rotating head of a power tool and an operative section for coupling with an external tool. The rod further includes an outer periphery having first and second positioning grooves and a positioning portion between the first and second positioning grooves. The operative section includes a coupling portion located in front of the second positioning groove and having a stopper edge wider than the positioning portion. A coupling end is provided at a front end of the operative section. A C-clip is mounted on the positioning portion of the rod. A jacket includes a receiving section slideably mounted around the positioning portion. The jacket further includes a coupling section located mounted around the coupling portion of the rod to rotate together with the rod. The receiving section includes a coupling groove for receiving the C-clip.

Abstract: A method for producing a drill bit includes preparing a metal shank and a metal drill, with the metal shank having a hardness greater than a hardness of the metal drill. Each of the metal shank and a metal drill includes an end having an end face. The metal shank and the metal drill are connected end to end, with the end face of the metal shank coaxially abutting the end face of the metal drill. The ends of the metal shank and the metal drill connected end to end are welded to form a molten pool at the welding area. A surface treatment is conducted on the welding area after welding. The welding area is annealed after the surface treatment.