The anatomy of a screw comes down to variations on a theme: threads, shank and head. Traditional screw designs usually feature a single thread, shallow pitch, larger diameter shank, and often a slotted head for hand driving. More often than not, such screws are limited to countersink, raised and round head types.
Newer designs have single or twin threads often with a much higher pitch, a narrow shank and a drive solution that suits power tools. We can now choose from self-drilling tips and self-seating heads, to different thread and shank lengths. And specialty features abound, including asymmetric threads, reverse threads, shank ribbing, exotic coatings and materials, a plethora of head choices, and so forth.
What differentiates screws for me is primarily the drive system, or the connection between the…