The Amphenol FCI 87185-421HLF is a 21-circuit single-row BERGSTIK II header in the board-to-board style. The 0.100 inch (2.54 mm) pitch, unshrouded male pin with square contact shape accepts the matching BERGSTIK II receptacle and is termination-qualified for through-hole solder assembly. Tin plating on both the mating interface and solder tail runs 100.0 µin (2.54 µm) thick — a full matte tin finish that handles reworking without the rework risk gold flash carries. The housing is black polyamide rated UL94 V-0.
Ratings that drive fit
The 5 A per circuit rating is the limiting spec here — 21 positions across a single row means the header fits a narrow board edge footprint, but the current demand across a power-dense board may require spreading the load across multiple circuits rather than pulling the full 5 A through a single pin. The 110 V rating is typical for signal-level board-to-board bussing and sits comfortably within what low-voltage logic rails need; it is not a power-distribution voltage. Contact material is phosphor bronze, which gives the spring beam the fatigue resistance needed for push-pull mating cycles.
Mating and termination
Push-pull fastening means this header relies on the insertion force of the mating receptacle to stay seated — there is no screw-lock or latch. For vibration-prone applications the board-side solder joints carry that load, not a retention feature. The 1.043 inch (26.49 mm) mating contact length gives the receptacle beam enough wipe travel to self-clean on insertion. The post length of 0.095 inch (2.41 mm) into the plated through hole is the board-side footprint dimension — check your paste mask and hole size against that entry to ensure the solder fill is complete on the first pass.