You will find here the information about:
How to fasten our product
What can of fasteners to use.
Note: You could find more info at my Pinterest page:
I suggest using this for stone.
The hole on the bracket is a bit more than 1/4’’.
You can also use Tapcon but personally, I don’t like it. Also is not fit well aesthetically.
It has also other fasteners in the markets. Ask your hardware associate. But from my experience, the nylon anchor is work well.
A trick: sometimes the anchor is a bit smaller than the hole. Especially if you use a metric anchor and drill with an imperial drill bit. You can twist a little copper or metal wire, as you find in an old electric wire, and insert it in the hole, it makes it very strong.