18-Position Header with Locking Ramp for Vibration-Prone Harnesses
The 0039299186 is a Molex Mini-Fit Jr 5566 series header, 18 circuits in two rows at 4.20 mm pitch — the same pitch as the matching crimp receptacle housing.
Board Footprint and Solder Anchoring
The board lock snaps into a plated through-hole and holds the header flush during reflow; no secondary hold-down fixture needed for most wave-solder profiles. Insulation height is 0.504" (12.80 mm) above the board — the vertical profile leaves clearance underneath for bottom-side components in a tight enclosure.
Mating Half and Contact Finish
This header mates with Mini-Fit Jr 5557 receptacle housings and 5556 crimp terminals. Tin works well in dry-circuit signal applications where the contact voltage wipes through any surface oxide on first mate. Contact material is brass, post finish is tin (35.0 µinch / 0.90 µm). The square pin geometry gives four contact points per circuit in the receptacle terminal, distributing the current load across the interface.
The base product number is 003929; this variant carries the full 18-position load in a tray package. No official cross-reference or pin-compatible alternate from Molex is listed — the Mini-Fit Jr 5566 series is the only direct fit.