NT coughed up some electrons that declared:


==Solid rivets==
Solid rivets are inserted into the hole and hammered flat, with the
workpiece resting on an anvil or similar. This is a much slower
process than blind riveting, and requires access to both sides of the
hole. The method has been in use for many centuries. These rivets are
usually copper or steel.

The final appearance is a flat disc or a domed head.

And countersunk - I know, we did steel riveting at school in metalwork

Cheers

Tim