Of the nails, i.e. of each of the nails or heads of those nails whereby the plates were fastened to the boards. The upper chambers; of which See Poole on "1 Chronicles 28:11".
Related Commentaries of 2 Chronicles 3:9
2 Chronicles 3:9
9 And the weight of the nails was fifty shekels of gold. And he overlaid the upper chambers with gold.