They start with two different things.
The Screw Itself: They begin with a big roll of metal wire. A crazy-fast machine snips a piece off and then smushes it—with a ton of pressure—into that rounded pan head shape. After that, another machine rolls the threads onto the shaft. It’s like clay, but with metal.
The Washer: This comes from a flat sheet of metal. Think of a giant hole punch. It just chomp-chomp-chomps, punching out perfect little rings, one after another after another. Its only job is to be a protective pad.
Here’s the magic. Instead of you getting two loose pieces in a bag, the factory puts the washer on for good. Usually, they use a method called spin assembly. A machine slides the washer onto the screw, then spins some tools around to gently squeeze the metal underneath it, creating a little collar. The washer is locked on for life, but it can still spin freely—which is exactly what you want when you’re driving it in.
Straight off the assembly line, they’re kind of plain and can rust. So, they take a bath. They might get a zinc coating for that shiny, silvery look and rust protection, or a darker, grippier finish. They do this after attaching the washer so it doesn’t get glued in place.
Why go through all this trouble?
You Can’t Lose the Washer: It’s permanently there. No more digging through a parts bag.
It’s Way Faster: On an assembly line, a robot arm just picks up one part, not two. Huge time saver.
It Just Works Better: Because the washer can spin, it sits flat against your material automatically, protecting it and spreading out the force.
