Usage: 2 forms in 2 verses
Form Translated As     In Verse(s)
περιχαλκώσεισ you shall brass plate LXX.Exod.27.6
περιχάλκωσεν he brass plated LXX.Exod.38.6

Liddell-Scott-Jones

περιχαλκόω (perichalkoō) to brass plate G:V

περιχαλκόω-όω,

cover with brass or copper, [LXX]

LSJ Scripture Refs: LXX.Exod.27.6