Albert Barnes Commentary Nehemiah 4:16

"And it came to pass from that time forth, that half of my servants wrought in the work, and half of them held the spears, the shields, and the bows, and the coats of mail; and the rulers were behind all the house of Judah." — Nehemiah 4:16 (ASV)

Habergeons - Or, “coats of mail.” Coats of mail were common in Assyria from the ninth century B.C., and in Egypt even earlier. They were made of thin laminae of bronze or iron, sewn upon leather or linen, and overlapping one another.