Identify a PCB female wire-to-board connector: steps and common series

You can identify a PCB female wire‑to‑board connector by measuring pitch to ±0.02 mm, counting positions/rows, noting entry angle and latch/key shapes, and matching those facts to known series (JST‑PH/XH/GH/SH, Molex KK 254/396, Mini‑Fit Jr, Hirose DF13).

What exactly is “female wire‑to‑board”?

On small‑pitch systems the cable side is the female housing with crimp sockets, while the PCB side is usually a shrouded male header. Some board receptacles are truly female, but the same measurements apply. Confirm which half you have before searching datasheets.

Measure these five things fast

• Positions and rows: e.g., 1×6, 2×5. Note vertical (top entry) or right‑angle (side entry).

• Pitch: measure center‑to‑center over n−1 intervals; 2.54, 2.50, 2.00, 1.25, 1.00, 3.96, and 4.20 mm are common. Example: 10 pins spanning 22.86 mm ⇒ 2.54 mm; 22.50 mm ⇒ 2.50 mm.

• Pin or pad size: through‑hole pins ~0.5–0.7 mm suggest 2.0–2.54 mm signal families; ≥1.1 mm suggests 3.96–4.20 mm power families. SMT parts at 1.0–1.25 mm often add metal hold‑downs at the shroud corners.

• Latch and polarization: friction ramp vs positive latch tab; front‑facing latch (JST‑GH) vs side key (Hirose DF13); blocked cavities or asymmetric shrouds are strong tells.

• Profile: very low mated height often indicates 1.0–1.25 mm; taller, boxy shrouds are typical of 2.0–2.54 mm; large power families are visibly wider with thicker walls.

How do I measure pitch cleanly with calipers?

Use a long baseline. For an n‑pin single row, measure from the center of pin 1 to the center of pin n and divide by n−1. If centers are hard to sight, use outer‑edge to outer‑edge of the row; the quotient is still the pitch. Distinguish 2.50 from 2.54 mm by measuring across at least 8–10 intervals; 0.04 mm/interval accumulates to ~0.32–0.40 mm difference.

2.50 mm or 2.54 mm — which is it?

At 2.54 mm, unshrouded square posts are common (Molex KK 254 and generics). At 2.50 mm, JST‑XH headers are shrouded with a tall, square body and matching cable housings with a positive latch. Footprints for 2.50 mm are tighter; mixing 2.50 and 2.54 mm stresses pins and should be avoided.

Visual cues for 1.0–1.25 mm series

JST‑SH (1.00 mm) is very low profile, almost always SMT, with a small latch bump; top‑ or side‑entry variants exist. At 1.25 mm, JST‑GH has a front‑facing latch on the cable housing and compact shrouded headers, while Hirose DF13 is taller with side polarization keys and often includes plastic locating pegs. These families are not cross‑mating despite equal pitch.

Large‑pitch power families at a glance

JST‑VH and Molex KK 396 (3.96 mm) have tall housings and large through‑hole pins around 1.1–1.3 mm; they’re intended for higher current. Molex Mini‑Fit Jr (4.20 mm) uses rectangular cable housings with side latch ears and robust shrouded board headers; it’s common in ATX‑style power harnesses.

Footprint‑only identification from the PCB

Even without the mating half, the PCB tells a story. Through‑hole pin diameter and annular ring size hint at current class. Asymmetric pad patterns and plastic peg holes indicate keyed, shrouded headers. For 1.0–1.25 mm SMT connectors, look for paired metal hold‑downs flanking fine‑pitch signal pads.

What wire gauges typically fit?

Typical terminal ranges: 1.0–1.25 mm series use 32–28 AWG; 2.0–2.54 mm use about 28–22 AWG; 3.96–4.20 mm power families accept roughly 18–14 AWG. Always verify the exact terminal part number for both conductor and insulation crimp windows.

How to document for a fast remote ID

Capture straight‑on photos of the mating face, top, and side with a scale in frame. Report pitch to 0.01 mm, row/position count, through‑hole pin diameter or SMT pad width, shroud width/height, and any latch/key details or molded part marks. These data points map unambiguously to a short list of candidates.

Build and compliance at HyperPCB

We support RoHS and REACH for hazardous substance control and build to IPC Class 2 or Class 3 acceptance criteria. Our ISO 9001:2015 certified QMS (SGS certificate CN‑2023‑Q1156, valid until June 2027) governs our processes. Quotes are returned within 24 hours and DFM feedback within 1 business day.