The First Half of the Part Number Isn't Enough
A lot of inquiry emails name only a series: "the DF14 cable," "that FI-X interface." A series name locates an interface family, but it doesn't pin down which exact part you need. Within one series, latched versus unlatched, thick gold versus thin gold, left-fed tape versus right-fed tape — the difference usually lives in the last segment or two of the part number. Whether the assembly drops into the chassis, whether the retention holds, whether the line feeds smoothly: the answers are all hiding in the back half.
Reading a part number as a compressed sentence beats memorizing brand names.
Taking a Part Number Apart
Manufacturers order the segments differently, but the dimensions they encode are the same across the board. A connector part number breaks down roughly like this:
| Part-number segment | What it encodes | Why it affects the assembly |
|---|---|---|
| Series name | The interface family (mechanical + electrical platform) | Sets the overall mating direction — a starting point, not the finish line |
| Pin count | Number of contacts | Sets the wiring order and channel grouping |
| Pitch | Contact center-to-center spacing | Sets the termination process and alignment precision |
| Mating direction | Wire side (plug/receptacle) / board side (header) | Wire side and board side can't be matched on the series name alone |
| Latch | Latched / unlatched / reverse-latch | Affects assembly method and retention |
| Plating | Gold / tin, and thickness | Affects mating-cycle life and cost |
| Packaging | Tape-and-reel / tray / bulk | Affects auto-feeding and minimum order quantity |
| Revision suffix | Manufacturer's internal revision, special changes | The segment that bites hardest on legacy replacements |
Not every part number carries all eight segments, but the moment the mating direction or the suffix is missing, engineering has to circle back and ask — and the sample schedule slips with it.
How to Read Three Common Families
What follows is a reading framework, not a lookup table. Treat each brand's own catalog as the authority on exact meaning.
- I-PEX: leans toward ultra-fine coax and board-to-board directions (CABLINE, the 20455 family and the like). The part number typically shows pin count + series number + variant suffix.
- Hirose DF series: mostly wire-to-board (DF13, the 1.25mm DF14, DF52, etc.). The number after "DF" is the series number, followed by pin count, pitch and a housing / terminal distinction.
- JAE FI series: common in display-panel interconnect (FI-X and others). Usually series + pin count + a latch / exit-direction suffix.
Remember one thing: the suffix conventions of these three makers don't carry over to one another — don't take what you learned on one brand and apply it to the next.
The Three Places the Suffix Bites Hardest
- Latch presence and orientation. Latched and unlatched versions look almost identical, but the retention they give once installed is very different — and the gap shows up more in a vibration environment in the field.
- Plating thickness. The dividing line between mating-cycle life and unit price often sits in the last segment of the part number; projects with frequent mate/unmate cycles especially need to read it closely.
- Packaging and tape feed direction. On an auto-feed line, a reversed tape direction stops the line outright — this is not a segment you want to discover only at goods receipt.
What to Spell Out When You Ask for a Quote
The more complete the information, the easier it is to judge whether the project calls for a connector review or should first go back to the pin-count or pitch spec page. We suggest providing, in one pass:
- The full part number, suffix included; when you only have the series name, attach the old part or board-side photos.
- The model number or photos of the mating end (board side / panel side).
- Pin count, pitch and the wiring-order definition — not pin count alone.
- The project stage: new development, legacy replacement, or a production cut-over.
Related Pages
- Micro-Coaxial Cable Assemblies
- eDP Assemblies Compatible with the I-PEX 20455 Interface
- LVDS Assemblies Compatible with the JAE FI-X Interface
- Further reading: What Is Connector Pitch
Reference
- I-PEX guide to connector product drawings — the manufacturer shows where recommended part numbers, pin-count variants, dimensions, mating parts, and part-number structure appear in a product drawing.
Trademark Notice
I-PEX® is a trademark of I-PEX Inc., Hirose™ of Hirose Electric Co., Ltd., and JAE™ of Japan Aviation Electronics Industry, Ltd.; the series names are their respective connector product-series identifiers. These names are referenced here solely to explain how part numbers are read and to identify mating interface directions. The assemblies described are compatible components independently designed and manufactured by EDPcable, which is not affiliated with, authorized by, or partnered with the owners above.
