Review on 🔧 Z Hex Flanged Internal Threaded Fasteners and Collated Fasteners with Enhanced SEO by John Banks

Very cheap. The first cracked when installed in the hole. I was told to use an 11mm drill bit. Since I used hickory, which is harder than pine, I use 7/16. A little more. As expected, I pinched the sides to keep the board from splitting. Well as soon as it was slightly above the level of the board the insert broke. It's no use anyway if they break and ruin the board.