pin header

A pin header is a connector made of individual metal pins arranged in one or more parallel rows, typically soldered to a printed circuit board (PCB). Each pin is a rigid conductor, usually 2.54 mm apart (standard spacing), with a square or round cross-section. The pins protrude from the board surface by 8 to 11 mm and accept a mating socket connector or jumper wire pushed onto them. This simplicity makes pin headers the most common way to break out signals on a development board, test fixture, or production panel.

Pin headers come in single-row, dual-row, and triple-row configurations. Single-row headers are basic: one line of pins useful for power, ground, or a small data bus. Dual-row headers pack two parallel lines into the same footprint; a 20-pin header measures roughly 2.54 mm by 5.08 mm at the base, shrinking twice the pins into minimal board real estate. Shrouded variants add a plastic housing around the pins to guide connectors and reduce the risk of crossed leads. Angled headers bend the pins 90 degrees, useful when vertical space is tight but horizontal reach is available.

The manufacturing process is straightforward: stamped or drawn wire pins are inserted into a plastic injection-molded insulator block, then soldered all at once in a wave or reflow oven. The insulator is often phenolic or polyamide plastic rated to 260°C, which must survive soldering heat. Current capacity per pin is modest; 2 amps per pin is typical for standard 0.1-inch pitch headers, though heavy-duty headers can handle 5 amps or more. Resistance across a pin is usually under 50 milliohms.

Common failure modes and naming confusion

Pin headers fail mainly from mechanical stress. Repeated insertion and removal wears the contact surfaces, increasing resistance and heat. Poor solder joints, especially around the base of the pin where mechanical bending concentrates stress, crack under thermal cycling. Corrosion of the pin metal (usually brass or tin-plated steel) reduces conductivity over months or years in humid environments. Because the mating connector is a passive socket with no latching mechanism, accidental partial insertion is common, leading to intermittent connections and false diagnostics.

The term "pin header" is industry standard but sometimes causes confusion with "header" alone, which in PCB design can mean any breakout connector. The older term "pin strip" is less common now. Socket headers (which have female sockets instead of pins) are the mating partner and are equally common; together they form a generic, reusable connection system that has dominated hobby and prototyping electronics since the 1990s. The 2.54 mm pitch is defined by IEC 61076, making headers and sockets from different manufacturers compatible.