What this connector is
The Amphenol FCI 86503-442HLF is the 42-position member of the BERGSTIK II dual-row pin header series — a board-to-board interconnect with 0.100 inch (2.54 mm) pitch on both the mating and row-spacing axes. Phosphor bronze contacts carry 5 A per circuit with tin plating on both the mating face (100 µin) and the solder-tail post. The header is unshrouded, push-pull fastened, and rated 110 V in a UL94 V-0 black thermoplastic housing.
What the ratings mean for the build
The 0.120 inch (3.05 mm) tail length supports standard through-hole insertion on thicker boards. At 5 A per circuit the header handles power distribution as easily as signal routing; the tin-on-tin interface is adequate for permanent board-to-board joins but the push-pull fastening carries no positive lock, so this is not a high-vibration panel I/O.
Where it is used
BERGSTIK II headers are common in industrial control boards, instrumentation, and telecom backplane cards — anywhere a controlled board-to-board stack uses an unshrouded header as a mid-plane or daughter-card feedthrough. The dual-row layout at 2.54 mm pitch is breadboard-compatible and accepted across most PCB design tool libraries. The UL94 V-0 rating clears the flammability bar for enclosed equipment housings.
Sourcing and availability
Listed Active. No official successor or cross-reference for this order code. The 42-position count is a non-standard circuit size in this series — confirm the BOM position count and the mating half before committing.