Tin Plating and Current Handling
The 77317-412-12LF: Tin-on-tin contacts are a workhorse choice for applications that mate infrequently — think once during assembly and maybe a handful of service cycles over the product life.
The closest functional alternative is the 77317-104-12LF — same 12 positions, same pitch, same right-angle through-hole layout, same black UL94 V-0 housing. The difference is the mating finish: this part (77317-412-12LF) uses tin on both sides; the 77317-104-12LF uses 30 µin gold GXT™ on the mating face. If your application calls for frequent reconnection — say, a test fixture or a field-swappable module — the gold-plated sibling will hold up longer. For a one-time harness build where the connector mates once and stays, the tin-on-tin version is the cost-effective pick.