0.40 mm Pitch, 40-Position Plug for High-Density Cable Assemblies
The Hirose DF81D-40P-0.4SD(52) is a 40-position plug from the DF81 series, built for high-density interconnects where board real estate is tight. The 0.016" (0.40 mm) pitch packs 40 circuits into a single-row, free-hanging package — the narrow spacing means the mating receptacle must match that pitch exactly, and the board footprint has zero room for routing error. The black housing accepts discrete or ribbon cable, terminated by soldering the conductors directly to the contacts — no crimp tooling required.
This plug accepts two wire gauge ranges: 34-36 AWG and 36-46 AWG. The dual range covers fine-wire ribbon cable (36-46 AWG) and slightly heavier discrete conductors (34-36 AWG). Termination is by soldering — the outer shroud contacts are designed for direct solder attachment, so the harness builder needs a soldering station, not a crimp press.
Position Count vs. Sibling: 40 vs. 50
The DF81D-40P-0.4SD(52) shares its 0.40 mm pitch, gold plating, and solder termination with the DF81D-50P-0.4SD(52). If the BOM calls for 40 positions, this is the match; the 50-position sibling is a genuine alternative only if the circuit count can be increased. No other spec changes between the two — same housing, same wire range, same lifecycle status.