Pin Headers & Dupont Connectors: China Sourcing Reference
Pin header and Dupont connector sourcing guide: 2.54mm/2.0mm/1.27mm pitch, brass vs gold plating, current ratings, through-hole vs SMD, SIL/DIL terminology, and Chinese manufacturers.
Pin headers and Dupont connectors are the most commoditized interconnect components in electronics. The 2.54 mm (0.1 inch) pitch standard originated with DIP IC sockets in the 1970s and has remained unchanged because it is human-scale — fingers can seat and unseat these connectors without tools. Chinese manufacturers supply the overwhelming majority of the global market for this format. Buying from Western distributors at 10–50× the Chinese factory price is a deliberate choice, not a necessity. The relevant question is not whether to source from China but which specification points to hold and which to not bother measuring.
Overview
A pin header is a row of press-fit or SMD pins held in a plastic housing at a defined pitch. The mating half is a Dupont-style housing with individual female crimp terminals, or a PCB-mount socket strip. The combination is used for:
- Development board I/O headers (Arduino, Raspberry Pi, STM32 Nucleo)
- Wire-to-board connections in production hardware
- Jumper blocks for configuration selection
- Interboard stacking in enclosures and development kits
The market splits into through-hole (THT) headers for hand assembly and prototyping, and SMD variants (right-angle SMD, gull-wing) for production boards where through-hole drilling is a cost or yield concern. SMD pin headers introduce their own problems during reflow — see the Common Issues section.
Key Specifications
| Parameter | 2.54 mm (standard) | 2.0 mm | 1.27 mm |
|---|---|---|---|
| Pitch | 2.54 mm (0.1”) | 2.0 mm | 1.27 mm (0.05”) |
| Typical current per pin | 3 A continuous | 2 A continuous | 1 A continuous |
| Contact material | Brass (CuZn), tin or gold plated | Brass, tin or gold plated | Brass, tin or gold plated |
| Housing material | PA66 (Nylon 66), black standard | PA66 or PBT | PA66 or LCP (for reflow) |
| Max operating temperature | 85°C (PA66) | 85°C (PA66) | 105°C (LCP for SMD) |
| Pin length (above insulator) | 11 mm standard; 6 mm and 15 mm available | Application-specific | Application-specific |
| Pin length (below insulator) | 3 mm standard (PCB thickness + wave solder) | 3 mm | 2.5 mm |
| Insulation resistance | ≥ 1,000 MΩ | ≥ 1,000 MΩ | ≥ 1,000 MΩ |
| Dielectric withstanding voltage | 500 VAC / 1 min | 500 VAC / 1 min | 300 VAC / 1 min |
Plating Options
| Plating | Thickness | Contact Resistance | Use Case |
|---|---|---|---|
| Tin over brass | 1–3 µm Sn | ≤ 20 mΩ initial | General prototyping, production where gold is not required |
| Selective gold (contact area) | 0.3–0.8 µm Au over Ni | ≤ 10 mΩ initial | Connections requiring ≥ 1,000 mating cycles |
| Full gold | 0.3–0.5 µm Au over Ni | ≤ 10 mΩ initial | High-cycle, corrosion-sensitive environments |
For most production applications, tin plating is sufficient and costs 30–60% less than gold. Specify “tin plating minimum 1 µm” in your purchase order — this filters out the cheapest bare-brass headers that oxidize visibly within 6 months in humid storage.
Main Variants
By Row Count
SIL (Single In Line): One row of pins. Standard for most GPIO headers, sensor breakouts, and jumper blocks. Also called “single row header.”
DIL (Dual In Line): Two parallel rows. Also called “double row header.” Used for memory modules, microcontroller sockets, and high-density I/O. Pin numbering convention: pin 1 is at top-left when the notch or marker is at top; pins count down the left column then up the right column (same as DIP IC).
By Mounting Orientation
Vertical (straight): Pins perpendicular to the PCB. Standard configuration. Mating connector plugs in from above.
Right angle: Pins exit parallel to the PCB. Used when mating connector must be accessible from the board edge. Right-angle headers have higher mechanical stress on the solder joint — the mating/unmating force is transmitted as a lever moment on the pin shoulder. Specify 90° tolerance ± 2° on the bend; Chinese commodity headers often ship at 85–95°.
Dupont Wire and Housing
The Dupont housing is the female counterpart: a rectangular PA66 housing with individual 2.54 mm pitch cavities. Each cavity holds one female crimp terminal. The terminal is stamped from phosphor bronze or brass, tin-plated, and crimped onto 26–28 AWG wire. Housing is typically 1×N or 2×N in 1, 2, 3, 4, 5, 6, 8, 10-pin configurations.
Standard female crimp terminal (254-style) has a box height of approximately 1.2 mm and accepts 26–28 AWG wire. Using 24 AWG wire requires a different terminal or a reduced-height crimp — a common mismatch in pre-made Dupont jumper wire sets where the wire is upsized for current capacity without changing the terminal.
Sourcing from China: What to Look For
Chinese manufacturers dominate this market to a degree unusual even by electronics component standards. BOOMELE (宝美乐), Ckmtw (产科), and Wcon (维连) collectively supply a large fraction of global demand for commodity 2.54 mm headers. This is not a market with a meaningful off-shore alternative — Harwin and Samtec make 2.54 mm headers but at 5–15× the price, justified only for specific mechanical or environmental requirements.
Approved Chinese suppliers for 2.54 mm headers:
| Supplier | Notes |
|---|---|
| BOOMELE (Shenzhen) | High-volume commodity; adequate tin plating; dimension tolerance generally ± 0.1 mm; no PPAP capability |
| Wcon Electronics (Dongguan) | Slightly higher spec than BOOMELE; offers gold plating option with consistent thickness; used by Chinese ODM factories in production |
| Ckmtw (产科, Shenzhen) | Commodity; popular in maker/development market; acceptable for prototyping and non-critical production |
| Shenzhen C&K (雄华) | Mid-tier; offers full custom specifications including housing color, pin length, and plating variant; MOQ 10,000 pcs |
Dimensional consistency is the only quality spec that matters at this price point. Request a first article with caliper measurement of:
- Pin pitch (should be 2.54 ± 0.05 mm across a 20-pin header)
- Pin straightness (deviation from vertical should be < 0.2 mm at pin tip)
- Insulator flatness (warpage < 0.3 mm across 40-pin header length)
Pin straightness and insulator flatness are where cheap headers fail. A header with a 0.5 mm warp on a 40-pin body will not seat flat in a socket strip and will apply uneven force across the mating contacts.
SMD vs. through-hole housing material. THT headers use PA66 (Nylon 66), which softens at 200°C and is not suitable for reflow. SMD right-angle headers must use PBT or LCP housing — LCP (Liquid Crystal Polymer) withstands 260°C reflow without deformation. Chinese suppliers frequently mislist PA66 headers as “SMD compatible.” Confirm housing material in the datasheet before specifying SMD headers for PCB assembly production reflow.
Current rating. The 3 A per pin figure for 2.54 mm headers is a thermal limit at 30°C ambient with specific wire gauge. In a 2×20 header carrying full GPIO current from a Raspberry Pi Compute Module (500 mA total, distributed across multiple pins), this is not a concern. In a power header carrying 5 V at 3 A through a single 2-pin header, the pin is at its thermal limit. For currents above 2 A on a single pin, specify the 2.54 mm heavy-duty variant (0.64 mm² pin cross-section rather than 0.4 mm²) or use a different connector family.
Common Issues
Pin straightness in production. Pin straightness degrades in storage — reel packaging causes the pins on the reel outer edge to bow slightly. When sourcing in bulk bags rather than tape-and-reel (common for commodity headers), straightness degrades further from compaction. Specify tape-and-reel packaging for headers used in automated insertion; loose bag headers are for hand assembly only.
Housing warpage during reflow. PA66 headers placed on a PCB in a reflow oven (even if not reflowed themselves, just passing through the oven for other components) can absorb enough heat to warp slightly. The effect is cumulative — boards that pass through reflow twice (double-sided) show more warpage. If headers are present on the bottom side of a double-reflow board, switch to PBT housing or manually solder headers after both reflow passes.
Plating uniformity on low-cost headers. The cheapest headers from Alibaba spot market have plating thickness that varies significantly between the base of the pin (inside the housing) and the tip. The tip is where mating occurs and where plating must be most uniform. When testing incoming headers, measure contact resistance at the pin tip, not at the housing solder tail — tip-resistance is what matters for signal integrity.
Dupont wire crimp quality. Pre-made Dupont jumper wires (10 cm, 20 cm, 30 cm female-to-female) are so cheap ($0.02–0.05 per wire) that crimp quality is rarely verified. Poorly crimped terminals have a pull-out force of 5–10 N rather than the specified 20 N. In a product where Dupont jumper wires connect internal modules, this becomes a field reliability issue. If Dupont wires are in your BOM for anything other than a development board, specify pull-force testing on incoming lots: 100% test at 20 N pull for 5 seconds is achievable with a simple test fixture and a spring scale.
Oxidation from bare-brass plating. Some suppliers ship bare brass (no plating) headers for maximum cost reduction. Bare brass oxidizes in humid environments within 3–6 months, raising contact resistance from < 20 mΩ to > 200 mΩ. Specify “tin-plated” explicitly and request a plating cross-section photo from the first article inspection.
Related Resources
- BOM Management — specification control for commodity components; how to lock plating and material specs in a BOM so substitutions are caught
- IPC-A-610 Acceptance Criteria — solder joint requirements for through-hole pin headers; wave solder fillet dimensions
- SMT Process — why PA66 housing headers cannot go through reflow; material selection for SMD variants
- How to Source Electronics from China — full guide to qualifying Chinese suppliers for commodity components
- Alibaba vs 1688 — sourcing connector commodities from 1688 factory direct vs. Alibaba distributors
- Supplier Sourcing & Matching
- PCB Manufacturing & SMT Sourcing
- PCB Assembly China Buyer’s Guide