The 12 A current rating is derated above 105°C ambient per the housing material curve; at 25°C it delivers full current without exceeding the contact temperature rise. Gold mating contacts at 30 µinch thickness contrast with the tin post finish — the gold side handles the mating wear, while the tin solder tail wets reliably during wave soldering. This split plating is standard for headers that mate with a receptacle in the field and then stay soldered for the board's life.
The 641963-3 carries a wider pitch (6.35 mm vs 4.20 mm), higher current per contact (12 A vs 5 A), and thicker gold plating (30 µinch vs 3 µinch). The 1318699-3 uses a latch lock instead of a locking ramp and offers a black housing versus natural.