Thread profile to reduce debris from thread breakage

摘要

To reduce the likelihood of fluid contamination from metallic debris caused during assembly by the breakage of partially formed lead-in and end threads (37',38' fig 3) of internally and externally threaded parts of a multi-component metallic housing for a fluid, such as a fuel injector housing (11, fig 1) and control valve 15 assembly, material of the partial threads (37',38') is removed either before or after the threads are machined into the part, leaving end thread convolutions 47,48 with a uniform profile. Short ramps 39,49 leading to the end thread convolutions 47,48 may be formed if removal of the partial threads is by milling.