If there's metal in the ones I'm talking about, it's mixed into the plastic before it's molded.
They look about the same on the outside but when you open them the inside is hollow, except for a couple of truss like ribs for strength.
No part of the plastic is thicker than, I would guess, 0.050", so there's nothing encapsulated.
The stiffening ribs would prevent having a lump of metal inside, that might have fallen out.
I've only seen a couple of them but I'll keep an eye out for one that I can open and photograph. Good shot for the closeups thread.
