What is this metal insert for in a desk?

[Swamp Thing]

This engineered wood table has metal inserts like this one fitted on the side and back boards, near the corners. Each board is 10 mm thick and the insert doesn't show on the other side of the board (the side facing outwards). I can also see an insert on the board that forms part of the chest of drawers, on the side supporting the drawers.

They don't seem to be fasteners holding anything together.

What would be the purpose of these?

 

[renormalize]

They don't seem to be fasteners holding anything together.
What would be the purpose of these?

Actually they do hold the wood pieces together. They're called Cam Lock fasteners:

(from https://www.amazon.com/LXLVOUEG-Locks-Furniture-Lock-Fasteners/dp/B0CQP9XMBF?tag=pfamazon01-20)

 

[A.T.]

Actually they do hold the wood pieces together. They're called Cam Lock fasteners:

Very familiar to anyone who puts IKEA stuff together (except that in recent years they often aren't made of metal anymore).

 

[Nik_2213]

Note metal Cam lock dowels may even be double-ended, for joining panels end-on.
A range of lengths available...
Discovered such when needed to 'Frankenstein' two flat-pack kitchen units as '50' + '40' cm, when range did not include a '90' cm and '100' cm would be 'Just Too Long'...
Yes, appropriate reinforcements affixed 'out of sight'...