Gender of connector: Female
Number of pins: 40 Pin
Type of row: Single-Row
Type of connector: Straight
2 x Single Row 40Pin 2.54mm Round Female Pin Header
Pin header connectors comprise several different means of connection. Generally, one side is a series of pins which are soldered to a PCB, and they can either be at a right-angle to the PCB surface (usually called “straight”) or parallel to the board’s surface (confusingly referred to as “right-angle” pins). Such connectors come in a variety of pitches, and may have any number of individual rows of pins.
The most commonly seen pin headers are 0.1″ (2.54mm) single or double row connectors. This is a standard breadboard compatible pitch. These come in male and female versions, and are the connectors used to connect Arduino boards and shields together. Users can easily connect jumper wires to breadboards.
Other pitches are not uncommon; for instance, the XBee wireless module uses a 2.0mm pitch version of the same connector. Below is a top view showing the SMD 2.00mm pitched female header soldered on the board. As you can see, the two rows of plated through holes for standard breadboard compatible headers next to the headers are spaced at 0.1″ (2.54mm) apart.
A common variation on this part is a “machine pin” version. While the normal version is formed out of stamped and folded sheet metal, machine pin connectors are formed by tooling the metal into the desired shape. The result is a more robust connector, with a better joint and longer life, making it somewhat more expensive.
Female machine pin headers. Note that these are designed to be snapped apart into smaller sections, while standard 0.1″ female header pin connectors are not. It’s also important to note that not all non-machine pin header connectors will mate with the machine pin variety.