Board-to-Board Stacking Fit
The 20021321-00006C4LF: This is a 6-position, dual-row receptacle from the Minitek127® 1.27mm series, designed for board-to-board stacking. The 1.27mm pitch and 1.27mm row spacing set the PCB footprint — each row of three contacts occupies a tight 3.81mm width, which keeps routing density high on the inner layers. The 4.50mm insulation height gives a moderate stack height for mezzanine applications where the board gap is between 5mm and 8mm, depending on the mating header's post length. In a low-vibration environment like a telecom line card or an industrial control board, that's fine. If the assembly sees shock or frequent cable strain, a header with a latch is a better call.
The mating surface carries 10.0µin gold over the phosphor bronze base. At this thickness, the connector is rated for a few hundred mating cycles — enough for board-level rework and field replacement, but not for frequent disconnect-reconnect duty like a test fixture.
Position Count Alternatives
The same base part number 20021321 covers a family of position counts. The 8-position sibling 20021321-00008C4LF shares the same pitch, gold plating thickness, and Tape & Reel packaging — the only difference is two extra contacts per row. If the BOM calls for 6 positions but the layout has room for 8, the 8-position part gives headroom for future signal count increases without a board spin.