What are these pins?
As mentioned in the comments, those swaged turret pins.
They are used to connect heavy guage wire to PCBs.
The pin itself is &quot;swaged&quot; onto the PCB - it is rather like a rivet.
The swaging provides mechanical strength.  The pin can also be soldered to the PCB to ensure a good electrical connection.
You can solder wires to the pins to connect things to the PCB.  You can also use clip on wires (alligator clips and similar things) to make temporary connections.  Oscilloscope probes will clip onto them as well.
They probably aren't much good for radio frequency stuff.  There's no way you can really make connection with a given impedance with them.