metric structural bolts

Countersunk self-drilling screws are a specific type of screw designed to allow for a flush finish in various materials, including wood, metal, and plastic. The term countersunk refers to the conical shape of the screw head, which allows it to sit seamlessly against the surface of the material being fastened. This design is particularly advantageous for aesthetics and functionality, as it eliminates any protruding heads that could be prone to snagging or catching on other objects.


...

A hex head bolt, named for its hexagonal-shaped head, is designed for use with a wrench or socket tool. The 8mm refers to the diameter of the bolt's shaft, which determines its load-bearing capacity. This size is commonly used in medium-duty applications where a balance between strength and ease of handling is necessary. The metric system, as opposed to imperial measurements, is employed here, reflecting the global acceptance and standardization of metric fasteners.

...