0.156" pitch, 5 positions, 4 loaded — footprint and keying
The 643495-3 is a single-row, vertical through-hole header from the MTA-156 series. It carries 5 positions on a 0.156" (3.96 mm) pitch, but only 4 positions are loaded with male square pins — the empty position serves as a keying feature to prevent mis-mating with the corresponding receptacle.
Tin-plated contacts for cost-sensitive builds
Tin is rated for 50–100 mating cycles — adequate for equipment that is wired once and rarely disconnected.
The header terminates via solder to the PCB through-hole.