What this DB-9 receptacle gives the board layout
The 750678-1: It terminates through-hole with solder tails and carries female screwlocks (4-40) on the mating face — the same thread pattern as the mating plug's hardware, so the pair stays cinched against vibration. The 6 A per-contact rating and 125 V dielectric cover signal-level duty in control cabinets, instrumentation panels, and serial communication ports.
Board locks — what they do for the assembly
During wave solder, they hold the connector square to the board so the solder joints on all 9 pins wet evenly.
Plating and temperature range — field-repair considerations
The steel shell with tin plating provides basic EMI shielding and mates with the standard D-sub grounding dimples on the plug side.
RoHS status — check before you spec
This part is listed as RoHS non-compliant. The tin plating on the steel shell and solder tails may contain lead above the exemption thresholds. For projects requiring full RoHS conformance, verify the target market's regulatory stance before committing the BOM line.