What pin diameter does 50865 accept?
The 50865 accepts a pin diameter range of 0.034" to 0.041" (0.86mm to 1.04mm) — this is the primary fit check. If your mating pin falls outside that window, the contact won't grip properly. The closed-bottom design means the socket has a solid base — no through-hole for the pin to exit. The pin seats against the bottom, and the beryllium copper contact beams provide the retention force.
Gold plating and contact material — why it matters
Beryllium copper itself handles the spring flex without taking a set over thousands of insertions. The socket depth is 0.247" (6.27mm), overall length 0.260" (6.60mm). The flange diameter is 0.089" (2.26mm), and the mounting hole diameter is 0.072" (1.83mm) — that hole size is what you drill in the PCB for the press-fit body.