These brilliant solder-able standoffs will make your mechanical PCB mounting problems go away. They're super simple - round M3 standoffs that are coated with tin so you can solder them in an oven or with a very powerful soldering iron & some patience. All you have to do is put a 4.25mm hole with 6.2mm solder ring on your PCB, then this components snout goes into the PCB, and solder it in place. The part is incredibly strong and saves you a hex nut or standoff. You don't even need a plated through hole (although it's recommend since they're stronger).
Fully threaded and works with any M3 machine screw