What is it?

This is a standoff for direct soldering to a PCB. This streamlines mounting the PCB to another surface or mounting a mechanical component such as a sensor or motor...a great time saver for robotics!

They are sold in packages of (5)

Why do I have them?

I have to attach custom PCBs to all sorts of devices, so I always have these handy.

To use in your PCB design, use a mounting hole with an M4 hole and solder pad. The hole is just big enough to accommodate the minor radius of the part and the pad provides enough space to apply solder.

If hand soldering, use plenty of flux and a sizeable chisel tip on the iron. When the nut becomes sufficiently hot, you will see a slight change in texture and even lead free solder will wet pretty well to the part.

What makes it special?

They aren't widely available...you can get them from Adafruit but sometimes they are out of stock. I don't ever intend to be out of stock.