| 摘要 |
A method and apparatus for repairing a casting in a cold metal repair process includes a plurality of drilling fixtures which facilitate the creation of one or more lock receiving recesses positioned generally transverse to the casting crack. The lock receiving recesses are formed of a single sized circular bore combination having alternating double and single circular portions to maximize strength. A plurality of correspondingly configured metal locks are inserted into the lock receiving recesses to provide transverse metal locks drawing the casting portions on each side of the crack together. A plurality of threaded bores are formed along the remainder of the casting crack in overlapping spacing which receive a corresponding plurality of stitching pins. The stitching pins each define threaded shaft portions having pointed ends and undersized major pitch diameter threads adjacent the pointed ends. A frusto-conical shoulder is formed on the opposite end of the threaded shaft and a break off drive head is coupled to the frustro-conical shoulder by a break off groove structure. When the stitching pins are inserted into their respective threaded bores, the undersized major pitch thread portions facilitate the threading the pin into the threaded bores. The pointed ends of the stitching pins provide complete filling of the threaded bores while the frustro-conical shoulder portions are operative to crush the first few threads of the threaded bores to enhance the seal obtained.
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