countersunk self drilling metal screws

The installation process of indented foundation bolts is meticulous and precise. Prior to concrete pouring, the bolts are positioned into pre-drilled holes, with their indents facing downwards. Once the concrete sets, the bolts are then tightened, causing the indentation to grip the concrete, forming a robust anchor. This method ensures that the bolt not only resists tension but also effectively transfers shear loads to the foundation.

...

Self-tapping screws, developed in the mid-20th century, eliminated the need for pre-drilling holes. These screws have a sharp point that cuts its own thread as it is screwed into the material These screws have a sharp point that cuts its own thread as it is screwed into the material These screws have a sharp point that cuts its own thread as it is screwed into the material These screws have a sharp point that cuts its own thread as it is screwed into the materialtek screw types. Self-tapping screws are commonly used in drywall, furniture assembly, and other applications where pre-drilling is not practical.

...