Board-edge fit and footprint
The 640389-6: The 0.125" (3.18mm) post length suits standard 1.6mm PCBs; the mating pin length of 0.400" (10.16mm) engages the full depth of the receptacle contact. The shrouded wall on one side guides the mating housing into alignment and protects the pins from accidental bending during assembly — a practical detail when the connector is near a board edge or behind a panel cutout.
Mating and retention in the harness
The lock engages audibly when the housing is fully seated; a tug on the wire confirms the pair is mated. Tin is suited for applications with fewer than 25 mating cycles and benign environments — in a corrosive or high-humidity setting, the tin surface can oxidise over time, increasing contact resistance.
Compliance and sourcing posture
No stock-holding claim; the part is procured through independent distribution channels per RFQ.