Pin header

On single row SMD headers the pins are bent alternating to one side or the other, on dual row SMD headers the pins are simply bent outwards.

If pin headers are optional, the THD variant is often chosen for ease of manual assembly.

Headers can be either straight (vertical) or right-angle, the latter form is sometimes used to connect two PCBs together horizontally.

A square notch (key) in the shroud prevents placing the connector (polarised by a "bump" on one side) the wrong way around.

Some systems polarize or key the pin header connection with something that fills and blocks one of the holes in the sockets.