The Hirose DF9C-31P-1V(22) is a 31-position, 2-row surface-mount header from the DF9 series, using center strip contacts on a 0.039" (1.00 mm) pitch. The 1.00 mm pitch packs 31 signals into a narrow body, which means the PCB footprint must match the tight centerline; a 0.050" pitch won't fit this pad layout.
Tin Contacts and the Mating Cycle Trade-off
If your assembly sees frequent reconnection or field-service disconnects, a gold-plated sibling in the DF9 family would hold up longer. For a one-time board-stacking assembly or a low-cycle production test point, the tin finish is perfectly adequate.
Surface Mount Assembly — No Solder Retention
This header is surface mount with no additional board guide or solder retention features on the body. During reflow, the part relies entirely on the solder paste's tack and the pad geometry to stay aligned. For high-vibration environments or high-speed pick-and-place lines, the DF9-31P-1V(32) adds a board guide and solder retention, and the DF9B-31P-1V(32) adds solder retention alone — both are drop-in alternatives at the same 1.00 mm pitch and 31 positions if you need extra mechanical hold before the solder solidifies.