The Hirose BM23PF0.8-24DP-0.35V(51) is a 24-position, dual-row header from the BM23 series, designed for board-to-board mezzanine stacking at a 0.8mm mated height.
Pitch and Stacking Height — The Fit Check
At 0.35mm pitch, this header demands a precise PCB footprint — the trace routing between pads is tight, and the solder mask registration needs to be on point. The 0.8mm mated stacking height is the dimension that decides the board-to-board gap: if your design calls for a 0.8mm standoff, this is the part. The height above board of 0.025" (0.63mm) tells you how much of that stack is the header itself, leaving the rest for the receptacle side.
Position Count and Series Siblings
The 24-position variant sits between the 20-position BM23PF0.8-20DP-0.35V(895) and the 30-position BM23PF0.8-30DP-0.35V(51) in the same BM23 series. If your BOM calls for 24 positions, this is the exact match; the 20- or 30-position siblings won't fit a 24-circuit layout without a board redesign.