Pitch and Pin Count — Board Fit First
The 77315-424-17LF: The 0.112" (2.84mm) post length gives enough solder fillet for a reliable through-hole joint on a standard 1.6mm board.
Contact Finish and Mating Cycles
That thickness provides a durable oxide barrier for low-cycle applications — think infrequent board swaps or test fixtures, not daily field-service reconnects. Tin is cost-optimised where gold's cycle-life advantage isn't needed. Phosphor bronze contact material gives good spring retention and corrosion resistance under the tin plating. The square pin shape mates with standard 0.025" square receptacles.