Samtec FTSH: 1.27mm Pitch Micro Header with Through-Hole Reliability in a High-Density Footprint

Samtec's FTSH series is a 1.27 mm (0.050") pitch micro header strip built on the company's Tiger Eye contact system. Unlike the more common 2.54 mm headers that eat up board real estate, the FTSH crams twice the signal density into the same linear space without dropping to the sub-millimeter pitches that make hand-soldering and rework painful. The through-hole termination means these parts stay put under repeated mating cycles and lateral cable stress — something surface-mount micro headers struggle with once the board flexes.

The multi-finger beryllium copper contact inside each pin socket produces a gas-tight connection rated for hundreds of mating cycles. When paired with the matching FTS/FTE socket strips, the mated pair handles per-pin current ratings that let it double as a low-power delivery rail in space-constrained designs.

Where These Show Up

In bench instrumentation, FTSH headers serve as the board-to-board interconnect between acquisition cards and backplanes in modular DAQ chassis — the through-hole anchor prevents the connector from walking off the board during thermal cycling. Test fixture builders use them as the spring-loaded contact interface between replaceable DUT adapter boards and the core measurement circuit. In aerospace telemetry units, the series appears on sensor interface boards where the vibration spec demands more than a surface-mount pad can guarantee. FPGA prototyping boards also lean on FTSH for mezzanine connections where the 1.27 mm pitch aligns with the 0.050" grid common on high-pin-count development carriers.

Key Selection Parameters

Choosing the Right Variant

Start with pin count and row configuration — that narrows the field fast. Pick dual-row unless the mechanical constraint genuinely forces single-row (single-row is harder to align during hand placement). Next, decide on plating: 10 μin gold gets the job done for lab prototypes and low-cycle production; jump to 30 μin if the connection will see more than 100 mate/demate cycles over its life, or if the board lives in a condensing-humidity environment where the extra gold buys corrosion margin. Tail length is usually standard unless the PCB exceeds 2 mm thickness. Add alignment pins when the board goes into a high-vibration enclosure or when the assembly team isn't using automated optical alignment — the mechanical keying saves mis-mate headaches later.

Compared to 2 mm Pitch Headers

The obvious alternative is the 2.00 mm pitch header grid (Hirose DF11, JST PH, or Samtec's own TMM series). Those give you larger solder pads and more forgiving hand-soldering margins, but you lose roughly 37% pin density per board inch. For a 20-pin connection, the FTSH at 1.27 mm saves about 15 mm of board edge compared to 2.00 mm — enough to fit an additional debug connector or status LED row on a constrained panel. The trade-off is that 1.27 mm pitch demands more precise drill registration in the PCB fab; cheap prototype houses that struggle with 0.6 mm annular rings will produce unreliable through-holes at this pitch.

Procurement Notes

Samtec ships FTSH as cut-to-length strips from a continuous reel, so lead times are typically shorter than custom-pinned connectors — stock configurations often ship same-day from Samtec's US facility. Distributor inventory skews toward popular pin counts (10, 20, 26, 32, 40, 50). If the exact count isn't in stock, order the next size up and snap to length with flush cutters — the breakaway design is rated for hand trimming without damaging adjacent positions. Be aware that the matching socket (FTS/FTE) is a separate part number and stocking decision; mismatched pairs are the most common procurement mistake on first orders.