The 643426-3: The 0.250" (6.35 mm) pitch and matching row spacing set the board layout and confirm compatibility with Universal MATE-N-LOK receptacle housings — the same pitch runs across the series, so a 9-position header mates with a 9-position plug housing without adapters. Three rows carry 9 circuits, all positions loaded.
Contact Interface and Cycle Life
In a panel that gets reconnected quarterly, the contact interface will outlast the enclosure's service life without corrosion or resistance drift. Tin on the post side matches standard solder processes.
Locking Ramp and Vibration Resistance
In an industrial cabinet near a motor drive, the ramp keeps the pair mated without loosening over time.
Housing and Environmental Rating
Natural nylon (polyamide) housing rated UL94 V-0 — the flame rating covers equipment inside an enclosure where flammability is a safety requirement.