What This Hardware Does
The TE Connectivity 5207953-3 is a jackscrew socket from the AMPLIMITE HD series — a D-sub accessory, not a connector body. It provides the female threaded receptacle half of the screwlock pair that secures a D-sub plug to its mating receptacle or panel. The 4-40 socket and 4-40 screw thread size means it accepts a standard 4-40 male jackscrew from the mating connector half. The 0.250" length below head sets the standoff between the connector face and the screw head, which determines how much panel thickness or bracket clearance the assembly needs.
This jackscrew socket is specified for use with AMPLIMITE Series HDE, HDF, and HDP D-subminiature connectors. Those are the standard-density and high-density D-sub families TE makes for I/O, serial, and industrial cabling. If you are assembling a cable harness or panel-mount D-sub using any of those series, this is the correct female screwlock hardware to retain the mated pair against vibration and cable strain. The 4-40 thread is the common size for standard D-sub hardware — not the smaller M3 or the larger 4-40 UNC found on high-power circulars.
Sourcing
The 4-40 thread and AMPLIMITE HD series are common enough that cross-references exist within the TE catalog, but no official second-source or direct substitute is listed on this record.