The Amphenol FCI BERGSTIK II 79425-166HLF is a 66-position, 2-row, 0.100-inch pitch unshrouded male pin header built for board-to-board interconnects in industrial and instrumentation applications. All 66 positions are loaded — no partial-population variants to reconcile. The connector uses square pin geometry, push-pull fastening, and mounts through hole with solder termination to the PCB. Contact plating is gold over phosphor bronze at 30.0 µin (0.76 µm) thickness on the mating interface, rated 5 A per circuit. The full stack of specs — 66 circuits, dual-row layout, 5 A per contact, and 110 V — puts this connector squarely in the dense-signal / moderate-power board-to-board category, where the position count is the primary BOM-match driver and the 0.100-inch pitch aligns with the most common 2.54 mm grid used across backplanes and daughtercard assemblies.
Key Specs and What They Mean
Position count and pitch: 66 positions across two rows at 0.100-inch (2.54 mm) pitch. The dual-row layout at this pitch gives a row spacing of 0.100 inch as well, which governs the PCB footprint and routing channel width between rows. The insulation height is 0.100 inch (2.54 mm) and overall contact length is 0.410 inch (10.41 mm), with the post extending 0.120 inch (3.05 mm) below the insulator and the mating-length portion entering the receptacle at 0.190 inch (4.83 mm). Current and voltage: 5 A per contact at 110 V. The UL94 V-0 insulator sets the thermal ceiling — verify ambient and adjacent-component heat load against the derating curve in the product drawing when drawing 5 A across all 66 circuits. Contact plating: gold at 30.0 µin (0.76 µm) over phosphor bronze. At this thickness the gold layer is sufficient for multiple mating cycles — the primary advantage over tin-plated variants is resistance to fretting corrosion and surface oxidation in field-service or repeated-connection scenarios. The contact shape is square, which provides self-cleaning alignment during insertion into the matching BERGSTIK II receptacle. Mounting and termination: through-hole solder. The post length below the insulator is 0.120 inch (3.05 mm) — adequate for standard PCB thicknesses in the single-digit mm range, but verify hole size and solder fill against the IPC class requirement for your assembly before specifying. Fastening type is push-pull, meaning the header relies on friction and header-receptacle geometry rather than a locking latch — confirm vibration exposure at the application level.
What the Ratings Mean for Your Application
Board-to-board style: the BERGSTIK II series is designed as a perpendicular or parallel board-to-board header. Because the header is unshrouded, it offers no polarisation keying on the connector body itself — if keyed-mating is required, the corresponding receptacle must provide the polarisation feature or a board-layout keying solution must be implemented. The push-pull fastening type reinforces that this is a light-duty latching interface suitable for stable, low-vibration environments or applications where the board stack is otherwise constrained. Flammability and insulation color: the UL94 V-0 rating means the insulator will not sustain a flame after ignition — critical in enclosed industrial enclosures or equipment where adjacent components could fail. The black insulator is standard for this series and carries no functional implication beyond visual contrast on the assembly. Package: ships in a bag — no tape-and-reel or tube packaging listed. For high-volume automated placement, confirm reel or tube availability through the franchise channel.