Rivets
Rivets will be more familiar to some of you.
Rivets are often used in model building to achieve a realistic representation.
Mainly used on tanks and other metal parts, e.g. bridges.
But also on wood, as I used them on my waterwheel.
I have tried everything, from greenstuff balls to the moisture-absorbing balls you often find in packaging.
Ultimately, I find the water purification material the easiest to use and available in various sizes.
I bought mine on sale for a few euros.
With enough stock, because there is a lot in such a package
Before using this material, it is handy to pre-drill a small hole so that it sits slightly recessed.
Apply metal paint over it and a black wash, then a light highlight of a metallic color, and you will have a perfect result.