I ordered some of these tins from a different source a while ago to store seeds. They work great for that, but the aluminum cases are fairly flimsy and flex easily. I don't think they would not hold up well to long term abuse, especially if you remove the round containers. That being said, they are perfect for sorting things that will be generally be out of harm's way. IIRC, the hinge is a simple aluminum pin. The ones I bought were these from American Science and Surplus.