What this header is and where it fits
The Amphenol 87901-418HLF is the 18-position member of the BERGSTIK II dual-row header series, configured for board-to-board stacking at the industry-standard 0.100" (2.54 mm) pitch. With 5 A per circuit and 110 V ratings, tin-plated phosphor bronze contacts, and through-hole solder termination, it covers the signal and low-power interconnect tier in industrial and instrumentation applications — a format that has been the default 2-row 0.100" footprint since the TTL era, and remains the go-to for board-to-board mezzanine and right-angle daughter-card stacking. The push-pull fastening type — as opposed to a lock latch — means the mating receptacle relies on contact normal force rather than an external latch; this matters when the pair will see vibration but no locking polarization is required. All 18 positions are loaded; the contacts are tin-plated at 100 µin (2.54 µm) on the mating face — this is a signal-duty plating grade, not the high-cycle gold tier, so the 5 A headline is sized for tin's current density, not for repeated reconnect cycling above a few dozen cycles. The housing is UL94 V-0 rated, which is the key flammability flag for enclosed equipment in industrial and telecom infrastructure.
Key ratings and what they mean for your design
Pitch and row spacing are both 0.100" (2.54 mm), so the footprint is the standard dual-row grid that mates with any 0.100" IDC ribbon receptacle, machine-pin socket, or daughter-card footprint built to the same grid. The 18 positions cover a moderate-density signal bus; if the design is power-forward rather than signal, the 5 A rating applies per contact at the listed voltage — the limiting factor is the cumulative thermal budget of the housing at the equipment ambient temperature. Contact shape is square pin, which is the legacy machine-pin footprint; it seats in round or square holes depending on the receptacle.
Sourcing and lifecycle
The part is marked Active — standard production, no EOL notice, sourced to order against the BOM quantity with no last-time-buy concern. The base product number 87901 places the 18-position variant within an established dual-row 0.100" BERGSTIK II family. No official successor code is listed; for any BOM substitution the 0.100" pitch, 18-position dual-row footprint, and tin-plated through-hole configuration are the non-negotiable cross-match criteria — any part that deviates on pitch, row count, or mounting type is not a form-fit-function replacement regardless of manufacturer.