Tyne sheild Boss

[Magnus]

Actually, as I understand it from Peronis, many shield bosses seem to have been attached with what might be best described as short bent nails. These would not have been as secure as rivets and we would probably be bothered by the rattling but it was obviously fine for the Romans. Such bent nails might easily fall out of an unattached shield boss or out of the remains of a shield being moved around by water currents. I do not think that the parade equipment idea holds up when there are simple explanations such as this to contrast with it.

Crispvs

It sounds to me like the shield boss itself would last longer than the shield, so perhaps this was a method in which the romans could swap bosses out on a shield easier. Bent nails are easier to remove than rivets.