Box Header Connector Cross-Reference: 2.54mm Part Numbers, Pin Maps and Pitch
Time:2026-07-07
Views:11
Every PCB that needs a latching wire-to-board connection ends up staring at a box header sooner or later. It‘s the connector with the little plastic shroud around the pins, the one that stops your crimp housing from wiggling off. If you‘ve ever fought with a plain pin header that let the cable pull loose in the middle of a test, you already know why the box version exists. This page is the cross-reference I wish someone handed me on day one: what the part numbers mean, which pitch you‘re actually holding, and how to source them without paying the Molex premium.
What a box header actually is
A box header is a male pin header with a raised plastic wall around the pins. That wall, sometimes called a shroud or a polarization key, is the whole point. It keys the mating housing so you can‘t plug it in backwards, and it gives the connection a bit of mechanical strength. Without it you‘ve got a bare pin header, and those are fine for jumpers but not much else. Most box headers are 2.54mm pitch, single or dual row, and come in straight (180°), right-angle (90°), and surface-mount (SMT) versions.
2.54mm is the default, and it‘s everywhere
When someone says "box header" without qualifying it, they mean 2.54mm. It‘s the same 0.1 inch grid as a standard DIP package, which is exactly why the Molex KK 254 family and every clone of it exist. Positions usually run from 2 to 40 in a dual-row layout, though single-row and three-piece socket versions show up too. If your board already has a 0.1 inch grid of through-holes, a 2.54mm box header drops straight in. You don‘t have to redo the layout.
Straight, right-angle, SMT: pick the one that fits
Three mounting styles cover almost every board. Straight (180°) headers point the cable up, which you want when the connector sits on a flat board with clearance above it. Right-angle (90°) headers lay the cable flat along the board edge, which saves height and is the go-to for panels and thin enclosures. SMT box headers mount on the surface so you don‘t need through-holes at all, handy for double-sided or high-density boards. There‘s also a low-profile IDC style and a press-fit version for when you can‘t solder. Each one changes the footprint, so check the drawing before you commit.
Reading the part number, so you don‘t order the wrong one
Box header part numbers look cryptic but they follow a pattern. Most Chinese factory numbering goes something like pitch + pin count + body type. A 2.54mm 16-pin dual-row straight box header will often read as something like "2.54 16P DIP box header" or carry a code for straight vs right-angle. The key fields you actually care about: pitch (2.54mm, 2.0mm, or 1.27mm), pin count, row count (single or dual), and mounting (DIP straight, right-angle, or SMT). If the drawing shows a shroud, it‘s a box header. If it‘s bare pins, it‘s not.
Box header specs side by side
| Item | 2.54mm | 2.0mm | 1.27mm |
|---|---|---|---|
| Typical use | General wire-to-board, Molex KK 254 compatible | Compact signal lines | High-density, ribbon cable |
| Rows | 1 or 2 | 1 or 2 | 2 (IDC / ribbon) |
| Positions | 2 to 40 | 2 to 30 | 10 to 50 |
| Rated current (typical) | 3A per contact | 1A per contact | 1A per contact |
| Housing material | PA66, UL94V-0 | PA66 / PBT, UL94V-0 | PA66 / LCP, UL94V-0 |
| Contact | Brass, tin plated | Brass, tin plated | Phosphor bronze, tin plated |
Box header vs Molex KK 254
The Molex KK 254 series is the branded 2.54mm wire-to-board family, and factory-direct box headers are its drop-in equivalent. Same 0.1 inch pitch, same footprint, same locking shroud. The difference is price and minimum order. Branded KK 254 housings and headers carry a part premium and often a minimum order quantity that hurts if you only need a few hundred pieces. A Shenzhen factory box header gives you the same fit at factory-direct pricing with a low MOQ, and you can spec custom pin counts or colors without a tooling fee. If your BOM says KK 254 and you‘re tired of the cost, this is the swap you can make without touching the PCB.
What to check before you order
Four things, and they‘ll save you a re-spin. First, the pin count and row count, because dual-row and single-row housings don‘t interchange. Second, the mounting style, since a straight header and a right-angle header have completely different footprints. Third, the mating housing, so the crimp terminal and wire gauge actually match the header. And fourth, the plating and material, because tin plating is the default and fine for most jobs, but you‘ll want gold or thicker plating if it‘s going to be unplugged a lot or live in a humid environment.
Frequently Asked Questions
What is a box header connector?
A male pin header with a plastic shroud around the pins that keys and locks the mating housing, usually 2.54mm pitch.
Is a box header the same as Molex KK 254?
Same 2.54mm pitch and footprint, so factory box headers are a drop-in equivalent at a lower price and MOQ.
What‘s the difference between a pin header and a box header?
The box header has a shroud that keys the housing and stops it pulling loose. A pin header is just bare pins.
Can I get a box header in right-angle or SMT?
Yes. Straight, 90° right-angle, and SMT versions are all standard, plus IDC and press-fit styles.
008613534059456
whatsapp:joy
overseas@hongyian.cn